id
string
topic
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difficulty
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math-001701
Linear Algebra: Linear Maps — Column Interpretation
1
Give a theorem-based solution: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-27&5\\-28&17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}25\...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-27\\cdot(25)+5\\cdot(-14)=-745$.", "Step 2: Second component: $-28\\cdot(25)+17\\cdot(-14)=-938$.", "Final step: Therefore $A...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-745,-938)^T$ here.", "robustness_analysis": "If the problem were perturb...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001702
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Exercise: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-3&16\\-15&-25\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-7\\-21\end{pmatrix}.$$...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-3\\cdot(-7)+16\\cdot(-21)=-315$.", "Step 2: Second component: $-15\\cdot(-7)+-25\\cdot(-21)=630$.", "Final step: Therefore $A...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-315,630)^T$ here.", "robustness_analysis": "If the problem were perturbe...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001703
Linear Algebra: Linear Maps — Column Interpretation
1
Answer with a short justification: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-28&-9\\26&-1\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}19\\-11\en...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-28\\\\26\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-9\\\\-1\\end{pmatrix}$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-433,505)^T$ here.", "robustness_analysis": "Ro...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001704
Linear Algebra: Vectors — Linear Combinations
1
Give reasoning, not just computation: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}13&-29\\26&-15\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}30\\-1...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}13\\\\26\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-29\\\\-15\\end{pmatrix}$...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(883,1035)^T$ here.", "robustness_analysis": "Se...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001705
Linear Algebra: Vectors — Linear Combinations
1
Where appropriate, name the theorem you use: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-2&13\\-5&-6\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}16\\-16\end{p...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-2\\cdot(16)+13\\cdot(-16)=-240$.", "Step 2: Second component: $-5\\cdot(16)+-6\\cdot(-16)=16$.", "Final step: Therefore $A\\m...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-240,16)^T$ here.", "robustness_analysis": "Robustness note: The column v...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001706
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Work this out carefully: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}20&11\\22&-8\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-20\\-20\end{pmatrix}.$$ (a) Com...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}20\\\\22\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}11\\\\-8\\end{pmatrix}$."...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-620,-280)^T$ here.", "robustness_analysis": "G...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001707
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Use two approaches if possible: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}7&11\\27&24\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}2\\2...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $7\\cdot(2)+11\\cdot(27)=311$.", "Step 2: Second component: $27\\cdot(2)+24\\cdot(27)=702$.", "Final step: Therefore $A\\mathbf...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(311,702)^T$ here.", "robustness_analysis": "If the problem were perturbed: The ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001708
Linear Algebra: Linear Maps — Column Interpretation
1
Try to avoid pattern-matching; explain why: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}30&-2\\7&21\end{pmatrix},\qquad \mathbf{v}=\begin{...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $30\\cdot(-12)+-2\\cdot(23)=-406$.", "Step 2: Second component: $7\\cdot(-12)+21\\cdot(23)=399$.", "Final step: Therefore $A\\m...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-406,399)^T$ here.", "robustness_analysis": "Ro...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001709
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Proceed methodically: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}11&19\\-15&-29\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}23\\-23\end...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $11\\cdot(23)+19\\cdot(-23)=-184$.", "Step 2: Second component: $-15\\cdot(23)+-29\\cdot(-23)=322$.", "Final step: Therefore $A...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-184,322)^T$ here.", "robustness_analysis": "If the problem were perturbed: The...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001710
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Write the solution set clearly: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}16&6\\18&-4\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}8\\-23\end{pmat...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $16\\cdot(8)+6\\cdot(-23)=-10$.", "Step 2: Second component: $18\\cdot(8)+-4\\cdot(-23)=236$.", "Final step: Therefore $A\\math...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-10,236)^T$ here.", "robustness_analysis": "Rob...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001711
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Derive the result step-by-step: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-26&-30\\7&-29\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-16\\15\end{...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-26\\cdot(-16)+-30\\cdot(15)=-34$.", "Step 2: Second component: $7\\cdot(-16)+-29\\cdot(15)=-547$.", "Final step: Therefore $A...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-34,-547)^T$ here.", "robustness_analysis": "Generality ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001712
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Solve with verification: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}8&16\\-19&28\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-20\\-30\end{pmatrix}...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $8\\cdot(-20)+16\\cdot(-30)=-640$.", "Step 2: Second component: $-19\\cdot(-20)+28\\cdot(-30)=-460$.", "Final step: Therefore $...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-640,-460)^T$ here.", "robustness_analysis": "If the pro...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001713
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Problem: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-3&13\\13&10\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}13\\8\end{pmatrix}.$$ (a) Compute $A\mathbf{v}$ ...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-3\\cdot(13)+13\\cdot(8)=65$.", "Step 2: Second component: $13\\cdot(13)+10\\cdot(8)=249$.", "Final step: Therefore $A\\mathbf...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(65,249)^T$ here.", "robustness_analysis": "Robu...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001714
Linear Algebra: Vectors — Linear Combinations
1
Give reasoning, not just computation: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}17&-17\\-15&5\end{pmatrix},\qquad \mathbf{v}=\begin{pmat...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}17\\\\-15\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-17\\\\5\\end{pmatrix}$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-663,305)^T$ here.", "robustness_analysis": "If...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001715
Linear Algebra: Vectors — Linear Combinations
1
Solve and justify each step: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-25&4\\20&29\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}17\\-6\end{pmatr...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-25\\cdot(17)+4\\cdot(-6)=-449$.", "Step 2: Second component: $20\\cdot(17)+29\\cdot(-6)=166$.", "Final step: Therefore $A\\ma...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-449,166)^T$ here.", "robustness_analysis": "If the problem were perturbed: The...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001716
Linear Algebra: Matrices — Action on Basis Vectors
1
Provide both a computational and a conceptual explanation: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}29&3\\8&-13\end{pmatrix},\qquad \ma...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}29\\\\8\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}3\\\\-13\\end{pmatrix}$.",...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-362,232)^T$ here.", "robustness_analysis": "Robustness note: The column ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001717
Linear Algebra: Vectors — Linear Combinations
1
Solve (and briefly cross-validate): Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-12&22\\29&-6\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-27\\-12\end{pmatrix}...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-12\\\\29\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}22\\\\-6\\end{pmatrix}$....
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(60,-711)^T$ here.", "robustness_analysis": "Generality n...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001718
Linear Algebra: Vectors — Linear Combinations
1
Track units/moduli carefully: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-13&2\\30&17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-26\\...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-13\\\\30\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}2\\\\17\\end{pmatrix}$."...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(308,-1035)^T$ here.", "robustness_analysis": "If the problem were perturb...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001719
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Carefully track domains: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-10&9\\-6&30\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-24\\0\end...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-10\\\\-6\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}9\\\\30\\end{pmatrix}$."...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(240,144)^T$ here.", "robustness_analysis": "If ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001720
Linear Algebra: Matrices — Action on Basis Vectors
1
Solve and include a self-check: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-30&9\\-28&18\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-4\\15\end{p...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-30\\cdot(-4)+9\\cdot(15)=255$.", "Step 2: Second component: $-28\\cdot(-4)+18\\cdot(15)=382$.", "Final step: Therefore $A\\ma...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(255,382)^T$ here.", "robustness_analysis": "Sensitivity ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001721
Linear Algebra: Matrices — Action on Basis Vectors
1
Make each step logically reversible (or explain if not): Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-8&11\\11&1\end{pmatrix},\qquad \math...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-8\\cdot(17)+11\\cdot(-5)=-191$.", "Step 2: Second component: $11\\cdot(17)+1\\cdot(-5)=182$.", "Final step: Therefore $A\\mat...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-191,182)^T$ here.", "robustness_analysis": "If the problem were perturbed: The...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001722
Linear Algebra: Linear Maps — Column Interpretation
1
Prompt: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}30&-6\\-29&-20\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}5\\-28\end{pmatrix}.$$ (a) Compute ...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}30\\\\-29\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-6\\\\-20\\end{pmatrix}$...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(318,415)^T$ here.", "robustness_analysis": "Gen...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001723
Linear Algebra: Matrices — Action on Basis Vectors
1
Determine the requested value: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}0&17\\-18&20\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}25\\-25\end{pma...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}0\\\\-18\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}17\\\\20\\end{pmatrix}$."...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-425,-950)^T$ here.", "robustness_analysis": "Generality note: The column view ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001724
Linear Algebra: Linear Maps — Column Interpretation
1
Derive the result step-by-step: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-1&25\\28&29\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-14\\-11\end{pmatrix}.$$ ...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-1\\cdot(-14)+25\\cdot(-11)=-261$.", "Step 2: Second component: $28\\cdot(-14)+29\\cdot(-11)=-711$.", "Final step: Therefore $...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-261,-711)^T$ here.", "robustness_analysis": "Sensitivit...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001725
Linear Algebra: Matrices — Action on Basis Vectors
1
Solve with verification: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-4&-14\\-22&29\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-10\\-30...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-4\\\\-22\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-14\\\\29\\end{pmatrix}$...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(460,-650)^T$ here.", "robustness_analysis": "Generality note: The column view g...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001726
Linear Algebra: Linear Maps — Column Interpretation
1
Prompt: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-21&6\\-14&-4\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}15\\4\end{pmatrix}.$$ (a) Compute $...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-21\\\\-14\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}6\\\\-4\\end{pmatrix}$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-291,-226)^T$ here.", "robustness_analysis": "G...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001727
Linear Algebra: Vectors — Linear Combinations
1
Checkpoint: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}20&14\\-12&-3\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-13\\-26\end{pmatrix}.$$ (a) Com...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $20\\cdot(-13)+14\\cdot(-26)=-624$.", "Step 2: Second component: $-12\\cdot(-13)+-3\\cdot(-26)=234$.", "Final step: Therefore $...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-624,234)^T$ here.", "robustness_analysis": "Generality ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001728
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Show all reasoning: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}23&16\\-5&27\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}19\\-27\end{pma...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}23\\\\-5\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}16\\\\27\\end{pmatrix}$."...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(5,-824)^T$ here.", "robustness_analysis": "Sensitivity analysis: The column vie...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001729
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Warm-up: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-25&10\\-18&-22\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-6\\-24\end{pmatrix}.$$ (a) Compute $A\mathbf...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-25\\cdot(-6)+10\\cdot(-24)=-90$.", "Step 2: Second component: $-18\\cdot(-6)+-22\\cdot(-24)=636$.", "Final step: Therefore $A...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-90,636)^T$ here.", "robustness_analysis": "Sensitivity analysis: The col...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001730
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Warm-up: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}11&-6\\2&21\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-23\\-19\end{pmatrix}.$$ (...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}11\\\\2\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-6\\\\21\\end{pmatrix}$.",...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-139,-445)^T$ here.", "robustness_analysis": "R...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001731
Linear Algebra: Matrices — Action on Basis Vectors
1
Indicate where a theorem is used: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-4&-5\\29&26\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-4\\cdot(-22)+-5\\cdot(4)=68$.", "Step 2: Second component: $29\\cdot(-22)+26\\cdot(4)=-534$.", "Final step: Therefore $A\\mat...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(68,-534)^T$ here.", "robustness_analysis": "Generality note: The column view ge...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001732
Linear Algebra: Vectors — Linear Combinations
1
Provide a rigorous solution: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-13&22\\-24&-28\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-26...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-13\\cdot(-26)+22\\cdot(7)=492$.", "Step 2: Second component: $-24\\cdot(-26)+-28\\cdot(7)=428$.", "Final step: Therefore $A\\...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(492,428)^T$ here.", "robustness_analysis": "Robustness note: The column v...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001733
Linear Algebra: Vectors — Linear Combinations
1
Show all reasoning: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}12&-26\\12&23\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-9\\-3\end{pmatrix}.$$ (a) Compute $...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $12\\cdot(-9)+-26\\cdot(-3)=-30$.", "Step 2: Second component: $12\\cdot(-9)+23\\cdot(-3)=-177$.", "Final step: Therefore $A\\m...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-30,-177)^T$ here.", "robustness_analysis": "Se...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001734
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Provide both a computational and a conceptual explanation: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}21&20\\12&22\end{pmatrix},\qquad \mathbf{v}=\b...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}21\\\\12\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}20\\\\22\\end{pmatrix}$."...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-38,158)^T$ here.", "robustness_analysis": "Robustness n...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001735
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Carefully track domains: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}18&9\\-13&2\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-11\\28\end{pmatrix}.$$ (a) Compu...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}18\\\\-13\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}9\\\\2\\end{pmatrix}$.",...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(54,199)^T$ here.", "robustness_analysis": "Robu...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001736
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Question: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-9&4\\8&-28\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-20\\-20\end{pmatrix}.$$ ...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-9\\\\8\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}4\\\\-28\\end{pmatrix}$.",...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(100,400)^T$ here.", "robustness_analysis": "Rob...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001737
Linear Algebra: Matrices — Action on Basis Vectors
1
Solve and justify each step: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}3&20\\17&-10\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-26\\-24\end{pma...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $3\\cdot(-26)+20\\cdot(-24)=-558$.", "Step 2: Second component: $17\\cdot(-26)+-10\\cdot(-24)=-202$.", "Final step: Therefore $...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-558,-202)^T$ here.", "robustness_analysis": "Sensitivit...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001738
Linear Algebra: Matrices — Action on Basis Vectors
1
Complete the analysis: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-10&-24\\1&17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}27\\1\end{pmatrix}.$$...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-10\\cdot(27)+-24\\cdot(1)=-294$.", "Step 2: Second component: $1\\cdot(27)+17\\cdot(1)=44$.", "Final step: Therefore $A\\math...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-294,44)^T$ here.", "robustness_analysis": "If ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001739
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Start by stating any domain restrictions: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}13&-15\\-18&17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $13\\cdot(-26)+-15\\cdot(-8)=-218$.", "Step 2: Second component: $-18\\cdot(-26)+17\\cdot(-8)=332$.", "Final step: Therefore $A...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-218,332)^T$ here.", "robustness_analysis": "Robustness note: The column view g...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001740
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Explain why your operations are valid: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-25&-14\\23&-13\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}3\\2...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-25\\\\23\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-14\\\\-13\\end{pmatrix}...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-411,-243)^T$ here.", "robustness_analysis": "Generality note: The column view ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001741
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Give a fully justified solution: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-2&13\\-27&24\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-2\\cdot(-30)+13\\cdot(-6)=-18$.", "Step 2: Second component: $-27\\cdot(-30)+24\\cdot(-6)=666$.", "Final step: Therefore $A\\...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-18,666)^T$ here.", "robustness_analysis": "Rob...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001742
Linear Algebra: Vectors — Linear Combinations
1
Use two approaches if possible: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-8&-23\\14&-20\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}2...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-8\\\\14\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-23\\\\-20\\end{pmatrix}$...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-452,68)^T$ here.", "robustness_analysis": "If the probl...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001743
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Give reasoning, not just computation: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-21&28\\-26&17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}13\\3...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-21\\cdot(13)+28\\cdot(3)=-189$.", "Step 2: Second component: $-26\\cdot(13)+17\\cdot(3)=-287$.", "Final step: Therefore $A\\m...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-189,-287)^T$ here.", "robustness_analysis": "Robustness note: The column...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001744
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Explain what is being counted/optimized: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}9&19\\12&20\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}18\\-19\end{pmatri...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}9\\\\12\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}19\\\\20\\end{pmatrix}$.",...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-199,-164)^T$ here.", "robustness_analysis": "S...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001745
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Solve and justify each step: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-13&-16\\26&-19\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-3\\12\end{pm...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-13\\cdot(-3)+-16\\cdot(12)=-153$.", "Step 2: Second component: $26\\cdot(-3)+-19\\cdot(12)=-306$.", "Final step: Therefore $A...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-153,-306)^T$ here.", "robustness_analysis": "Generality note: The column...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001746
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Solve with verification: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-2&-29\\-28&-20\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-28\\-30\end{pmat...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-2\\\\-28\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-29\\\\-20\\end{pmatrix}...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(926,1384)^T$ here.", "robustness_analysis": "Se...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001747
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Write the solution set clearly: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}23&-13\\-18&17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}13\\22\end{p...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}23\\\\-18\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-13\\\\17\\end{pmatrix}$...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(13,140)^T$ here.", "robustness_analysis": "If the problem were perturbed: The c...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001748
Linear Algebra: Linear Maps — Column Interpretation
1
Answer using clear logical steps: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-12&9\\-5&-6\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-28\\-29\end...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-12\\cdot(-28)+9\\cdot(-29)=75$.", "Step 2: Second component: $-5\\cdot(-28)+-6\\cdot(-29)=314$.", "Final step: Therefore $A\\...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(75,314)^T$ here.", "robustness_analysis": "If the problem were perturbed: The c...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001749
Linear Algebra: Linear Maps — Column Interpretation
1
Work carefully and justify each inference: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-28&-3\\-7&-9\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-4\\1\end{pmat...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-28\\\\-7\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-3\\\\-9\\end{pmatrix}$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(109,19)^T$ here.", "robustness_analysis": "Gene...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001750
Linear Algebra: Matrices — Action on Basis Vectors
1
Where appropriate, name the theorem you use: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-6&16\\1&0\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}23\...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-6\\cdot(23)+16\\cdot(-12)=-330$.", "Step 2: Second component: $1\\cdot(23)+0\\cdot(-12)=23$.", "Final step: Therefore $A\\mat...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-330,23)^T$ here.", "robustness_analysis": "Sensitivity analysis: The column vi...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001751
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Where appropriate, name the theorem you use: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-13&6\\-4&19\end{pmatrix},\qquad \mathbf{v}=\begi...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-13\\cdot(-10)+6\\cdot(2)=142$.", "Step 2: Second component: $-4\\cdot(-10)+19\\cdot(2)=78$.", "Final step: Therefore $A\\math...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(142,78)^T$ here.", "robustness_analysis": "Robustness note: The column vi...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001752
Linear Algebra: Linear Maps — Column Interpretation
1
Checkpoint: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}26&6\\-19&-4\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}27\\-16\end{pmatrix}.$$ (a) Comp...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}26\\\\-19\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}6\\\\-4\\end{pmatrix}$."...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(606,-449)^T$ here.", "robustness_analysis": "Sensitivity analysis: The co...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001753
Linear Algebra: Matrices — Action on Basis Vectors
1
Checkpoint: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-8&23\\-11&17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}11\\12\end{pmatrix}.$$ (a) Compute $A\mathbf...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-8\\\\-11\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}23\\\\17\\end{pmatrix}$....
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(188,83)^T$ here.", "robustness_analysis": "Sens...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001754
Linear Algebra: Linear Maps — Column Interpretation
1
Answer with a short justification: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-4&-28\\25&20\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}6\\-5\end{pmatrix}.$$ ...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-4\\cdot(6)+-28\\cdot(-5)=116$.", "Step 2: Second component: $25\\cdot(6)+20\\cdot(-5)=50$.", "Final step: Therefore $A\\mathb...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(116,50)^T$ here.", "robustness_analysis": "Robustness note: The column vi...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001755
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Carefully track domains: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-11&-25\\-4&26\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}0\\-2\en...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-11\\\\-4\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-25\\\\26\\end{pmatrix}$...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(50,-52)^T$ here.", "robustness_analysis": "Robustness note: The column view gen...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001756
Linear Algebra: Vectors — Linear Combinations
1
Be explicit about assumptions: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}3&-24\\-4&-17\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-5\\29\end{pmatrix}.$$ (a...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}3\\\\-4\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-24\\\\-17\\end{pmatrix}$....
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-711,-473)^T$ here.", "robustness_analysis": "Robustness...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001757
Linear Algebra: Vectors — Linear Combinations
1
Explain what is being counted/optimized: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}18&22\\-13&-2\end{pmatrix},\qquad \mathbf{v}=\begin{p...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}18\\\\-13\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}22\\\\-2\\end{pmatrix}$....
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(370,-295)^T$ here.", "robustness_analysis": "Sensitivity...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001758
Linear Algebra: Linear Maps — Column Interpretation
1
Solve and then verify: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}1&-1\\30&21\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-22\\-8\end{pmatrix}.$$...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}1\\\\30\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-1\\\\21\\end{pmatrix}$.",...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-14,-828)^T$ here.", "robustness_analysis": "Generality note: The column ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001759
Linear Algebra: Linear Maps — Column Interpretation
1
Prompt: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-4&-10\\-6&2\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}10\\-1\end{pmatrix}.$$ (a) Compute $A\mathbf{v}$ ...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-4\\cdot(10)+-10\\cdot(-1)=-30$.", "Step 2: Second component: $-6\\cdot(10)+2\\cdot(-1)=-62$.", "Final step: Therefore $A\\mat...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-30,-62)^T$ here.", "robustness_analysis": "Generality note: The column v...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001760
Linear Algebra: Matrices — Action on Basis Vectors
1
Solve and include a self-check: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}19&1\\16&18\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-20\\11\end{pma...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $19\\cdot(-20)+1\\cdot(11)=-369$.", "Step 2: Second component: $16\\cdot(-20)+18\\cdot(11)=-122$.", "Final step: Therefore $A\\...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-369,-122)^T$ here.", "robustness_analysis": "If the problem were perturb...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001761
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Provide a rigorous solution: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-10&16\\29&19\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}10\\-...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-10\\\\29\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}16\\\\19\\end{pmatrix}$....
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-116,271)^T$ here.", "robustness_analysis": "Robustness note: The column view g...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001762
Linear Algebra: Matrices — Action on Basis Vectors
1
Solve and include a self-check: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-2&-16\\-10&4\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-3\\-25\end{...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-2\\\\-10\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-16\\\\4\\end{pmatrix}$....
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(406,-70)^T$ here.", "robustness_analysis": "Generality n...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001763
Linear Algebra: Vectors — Linear Combinations
1
Explain what is being counted/optimized: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-23&-22\\-10&10\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}4\...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-23\\\\-10\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-22\\\\10\\end{pmatrix}...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-202,10)^T$ here.", "robustness_analysis": "Rob...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001764
Linear Algebra: Linear Maps — Column Interpretation
1
Provide both a computational and a conceptual explanation: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-13&10\\2&30\end{pmatrix},\qquad \mathbf{v}=\...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-13\\cdot(-24)+10\\cdot(-17)=142$.", "Step 2: Second component: $2\\cdot(-24)+30\\cdot(-17)=-558$.", "Final step: Therefore $A...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(142,-558)^T$ here.", "robustness_analysis": "If the problem were perturbe...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001765
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Carefully track domains: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}17&-12\\-23&2\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}29\\13\end{pmatrix}.$$ (a) Comp...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $17\\cdot(29)+-12\\cdot(13)=337$.", "Step 2: Second component: $-23\\cdot(29)+2\\cdot(13)=-641$.", "Final step: Therefore $A\\m...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(337,-641)^T$ here.", "robustness_analysis": "Generality note: The column view g...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001766
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Determine the requested value: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-4&-9\\-25&-8\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-25...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-4\\\\-25\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-9\\\\-8\\end{pmatrix}$....
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(370,865)^T$ here.", "robustness_analysis": "Sensitivity analysis: The column vi...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001767
Linear Algebra: Linear Maps — Column Interpretation
1
Do not skip justification steps: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-24&-14\\6&-4\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-20\\-17\end{pmatrix}.$$...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-24\\cdot(-20)+-14\\cdot(-17)=718$.", "Step 2: Second component: $6\\cdot(-20)+-4\\cdot(-17)=-52$.", "Final step: Therefore $A...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(718,-52)^T$ here.", "robustness_analysis": "Robustness n...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001768
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Challenge: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}14&-13\\23&28\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-27\\-23\end{pmatrix}.$$ (a) Comp...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $14\\cdot(-27)+-13\\cdot(-23)=-79$.", "Step 2: Second component: $23\\cdot(-27)+28\\cdot(-23)=-1265$.", "Final step: Therefore ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-79,-1265)^T$ here.", "robustness_analysis": "Robustness...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001769
Linear Algebra: Linear Maps — Column Interpretation
1
Carefully track domains: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}3&-15\\6&22\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-3\\-19\end{pmatrix}.$$ (a) Compu...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}3\\\\6\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-15\\\\22\\end{pmatrix}$.",...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(276,-436)^T$ here.", "robustness_analysis": "Generality note: The column ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001770
Linear Algebra: Vectors — Linear Combinations
1
Start by stating any domain restrictions: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}0&15\\-26&5\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-14\\-22\end{pmat...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $0\\cdot(-14)+15\\cdot(-22)=-330$.", "Step 2: Second component: $-26\\cdot(-14)+5\\cdot(-22)=254$.", "Final step: Therefore $A\...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-330,254)^T$ here.", "robustness_analysis": "Ge...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001771
Linear Algebra: Matrices — Action on Basis Vectors
1
Explain what is being counted/optimized: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-18&-15\\-11&-23\end{pmatrix},\qquad \mathbf{v}=\begi...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-18\\\\-11\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-15\\\\-23\\end{pmatrix...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-168,-407)^T$ here.", "robustness_analysis": "Robustness note: The column view ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001772
Linear Algebra: Matrices — Action on Basis Vectors
1
Problem: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}24&-5\\-20&4\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-3\\-5\end{pmatrix}.$$ (a) Compute ...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}24\\\\-20\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-5\\\\4\\end{pmatrix}$."...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-47,40)^T$ here.", "robustness_analysis": "Robustness note: The column vi...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001773
Linear Algebra: Vectors — Linear Combinations
1
Complete the analysis: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-13&-13\\25&7\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}18\\-10\end{pmatrix}....
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-13\\cdot(18)+-13\\cdot(-10)=-104$.", "Step 2: Second component: $25\\cdot(18)+7\\cdot(-10)=380$.", "Final step: Therefore $A\...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-104,380)^T$ here.", "robustness_analysis": "Ge...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001774
Linear Algebra: Linear Maps — Column Interpretation
1
Give a theorem-based solution: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-15&-9\\27&-23\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-1\\5\end{pmatrix}.$$ (a...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-15\\cdot(-1)+-9\\cdot(5)=-30$.", "Step 2: Second component: $27\\cdot(-1)+-23\\cdot(5)=-142$.", "Final step: Therefore $A\\ma...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-30,-142)^T$ here.", "robustness_analysis": "Robustness note: The column ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001775
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Give an answer and a quick verification: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-9&20\\-25&-9\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-22...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-9\\cdot(-22)+20\\cdot(27)=738$.", "Step 2: Second component: $-25\\cdot(-22)+-9\\cdot(27)=307$.", "Final step: Therefore $A\\...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(738,307)^T$ here.", "robustness_analysis": "Robustness note: The column v...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001776
Linear Algebra: Vectors — Linear Combinations
1
Checkpoint: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-19&3\\-21&-19\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}12\\-18\end{pmatrix}.$$ (a) Com...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-19\\\\-21\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}3\\\\-19\\end{pmatrix}$...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-282,90)^T$ here.", "robustness_analysis": "If the probl...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001777
Linear Algebra: Linear Maps — Column Interpretation
1
Indicate where a theorem is used: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}12&-28\\2&3\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}28\\4\end{pmatrix}.$$ (a...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}12\\\\2\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-28\\\\3\\end{pmatrix}$.",...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(224,68)^T$ here.", "robustness_analysis": "Robustness note: The column vi...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001778
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Task: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}15&-5\\11&8\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-27\\-6\end{pmatrix}.$$ (a) Compute $A\...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $15\\cdot(-27)+-5\\cdot(-6)=-375$.", "Step 2: Second component: $11\\cdot(-27)+8\\cdot(-6)=-345$.", "Final step: Therefore $A\\...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-375,-345)^T$ here.", "robustness_analysis": "Robustness...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001779
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Answer with a short justification: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}28&-20\\-19&25\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}9\\20\end...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $28\\cdot(9)+-20\\cdot(20)=-148$.", "Step 2: Second component: $-19\\cdot(9)+25\\cdot(20)=329$.", "Final step: Therefore $A\\ma...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-148,329)^T$ here.", "robustness_analysis": "Se...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001780
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Challenge: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}16&-14\\-15&-13\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}10\\26\end{pmatrix}.$$ (a) Comp...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}16\\\\-15\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-14\\\\-13\\end{pmatrix}...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-204,-488)^T$ here.", "robustness_analysis": "R...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001781
Linear Algebra: Vectors — Linear Combinations
1
Give a theorem-based solution: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}27&-26\\24&21\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-23\\-20\end{pmatrix}.$$ ...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}27\\\\24\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-26\\\\21\\end{pmatrix}$....
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-101,-972)^T$ here.", "robustness_analysis": "Sensitivity analysis: The column ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001782
Linear Algebra: Matrices — Action on Basis Vectors
1
Question: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-5&16\\-28&7\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-12\\11\end{pmatrix}.$$ ...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-5\\\\-28\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}16\\\\7\\end{pmatrix}$."...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(236,413)^T$ here.", "robustness_analysis": "Robustness n...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001783
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Track quantifiers carefully: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-8&0\\11&-15\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-26\\7\end{pmatri...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-8\\cdot(-26)+0\\cdot(7)=208$.", "Step 2: Second component: $11\\cdot(-26)+-15\\cdot(7)=-391$.", "Final step: Therefore $A\\ma...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(208,-391)^T$ here.", "robustness_analysis": "Sensitivity analysis: The column v...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001784
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Start by stating any domain restrictions: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}5&-18\\-20&-18\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-18\\1\end{pma...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $5\\cdot(-18)+-18\\cdot(1)=-108$.", "Step 2: Second component: $-20\\cdot(-18)+-18\\cdot(1)=342$.", "Final step: Therefore $A\\...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-108,342)^T$ here.", "robustness_analysis": "Generality note: The column ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001785
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Give a theorem-based solution: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}7&18\\-23&9\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}18\\14\end{pmatr...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}7\\\\-23\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}18\\\\9\\end{pmatrix}$.",...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(378,-288)^T$ here.", "robustness_analysis": "Ge...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001786
Linear Algebra: Linear Maps — Column Interpretation
1
Work carefully and justify each inference: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}25&18\\6&-27\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}20...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}25\\\\6\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}18\\\\-27\\end{pmatrix}$."...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(392,282)^T$ here.", "robustness_analysis": "Generality n...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001787
Linear Algebra: Vectors — Linear Combinations
1
Solve and then verify: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-16&6\\9&12\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-22\\-24\end{...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-16\\\\9\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}6\\\\12\\end{pmatrix}$.",...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(208,-486)^T$ here.", "robustness_analysis": "If the problem were perturbe...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001788
Linear Algebra: Matrices — Action on Basis Vectors
1
Show all reasoning: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}26&2\\2&13\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}9\\-23\end{pmatrix}.$$ (a) Compute $A\m...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}26\\\\2\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}2\\\\13\\end{pmatrix}$.", ...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(188,-281)^T$ here.", "robustness_analysis": "Generality ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001789
Linear Algebra: Vectors — Linear Combinations
1
Answer using clear logical steps: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-5&-26\\10&-14\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-15\\-9\en...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-5\\\\10\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-26\\\\-14\\end{pmatrix}$...
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(309,-24)^T$ here.", "robustness_analysis": "Robustness note: The column view ge...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001790
Linear Algebra: Linear Maps — Column Interpretation
1
Checkpoint: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-22&25\\-14&12\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-21\\-2\end{pmatrix}.$$ (a) Compute $A\math...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-22\\cdot(-21)+25\\cdot(-2)=412$.", "Step 2: Second component: $-14\\cdot(-21)+12\\cdot(-2)=270$.", "Final step: Therefore $A\...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(412,270)^T$ here.", "robustness_analysis": "If the probl...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001791
Linear Algebra: Matrices — Action on Basis Vectors
1
Solve and justify each step: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}15&-7\\21&-16\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-4\\7...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}15\\\\21\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-7\\\\-16\\end{pmatrix}$....
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-109,-196)^T$ here.", "robustness_analysis": "Robustness note: The column...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Key idea: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001792
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Compute the requested quantity: Find $A\mathbf{v}$, then rewrite it explicitly as $x\mathbf{a}_1+y\mathbf{a}_2$ where $\mathbf{a}_i$ are columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}1&-10\\-13&7\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-30\\19\end{p...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $1\\cdot(-30)+-10\\cdot(19)=-220$.", "Step 2: Second component: $-13\\cdot(-30)+7\\cdot(19)=523$.", "Final step: Therefore $A\\...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-220,523)^T$ here.", "robustness_analysis": "Robustness ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001793
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Where appropriate, name the theorem you use: Evaluate $A\mathbf{v}$ and provide both a computational and a conceptual (column-space) explanation: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}3&14\\-5&-27\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-20\\20\end{p...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $3\\cdot(-20)+14\\cdot(20)=220$.", "Step 2: Second component: $-5\\cdot(-20)+-27\\cdot(20)=-440$.", "Final step: Therefore $A\\...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(220,-440)^T$ here.", "robustness_analysis": "Ro...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001794
Linear Algebra: Matrices — Action on Basis Vectors
1
Try to avoid pattern-matching; explain why: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}6&6\\16&5\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}2\\5\...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $6\\cdot(2)+6\\cdot(5)=42$.", "Step 2: Second component: $16\\cdot(2)+5\\cdot(5)=57$.", "Final step: Therefore $A\\mathbf{v}=\\...
{ "consistency_check": "Cross-check: both derivations land on the same invariant quantity. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(42,57)^T$ here.", "robustness_analysis": "If the problem...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001795
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
State any required conditions first: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-26&22\\-6&13\end{pmatrix},\qquad \mathbf{v}=\begin{pmatr...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}-26\\\\-6\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}22\\\\13\\end{pmatrix}$....
{ "consistency_check": "Both approaches agree after simplification. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(1330,505)^T$ here.", "robustness_analysis": "Sensitivity analysis: The column v...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)
math-001796
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Find the exact value: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}-22&-29\\21&0\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}-24\\2\end{p...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $-22\\cdot(-24)+-29\\cdot(2)=470$.", "Step 2: Second component: $21\\cdot(-24)+0\\cdot(2)=-504$.", "Final step: Therefore $A\\m...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(470,-504)^T$ here.", "robustness_analysis": "Sensitivity analysis: The co...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001797
Linear Algebra: Coordinate-Free Meaning of $A\mathbf{v}$
1
Complete the analysis: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}15&-25\\19&-24\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}7\\13\end{...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}15\\\\19\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-25\\\\-24\\end{pmatrix}$...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-220,-179)^T$ here.", "robustness_analysis": "S...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Takeaway: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001798
Linear Algebra: Matrices — Action on Basis Vectors
1
Make each step logically reversible (or explain if not): Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}26&20\\-15&19\end{pmatrix},\qquad \ma...
[ { "method_name": "Row-by-Column", "approach": "Each output entry is the dot product of a row of $A$ with $\\mathbf{v}$.", "steps": [ "Step 1: First component: $26\\cdot(0)+20\\cdot(-5)=-100$.", "Step 2: Second component: $-15\\cdot(0)+19\\cdot(-5)=-95$.", "Final step: Therefore $A\\mat...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(-100,-95)^T$ here.", "robustness_analysis": "Robustness note: The column ...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001799
Linear Algebra: Vectors — Linear Combinations
1
Give an answer and a quick verification: Matrix-vector multiplication: compute $A\mathbf{v}$ and interpret the result as a linear combination of columns: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}22&-30\\16&2\end{pmatrix},\qquad \mathbf{v}=\begin{pmatrix}20\\7...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}22\\\\16\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-30\\\\2\\end{pmatrix}$."...
{ "consistency_check": "The two methods are consistent and must coincide. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(230,334)^T$ here.", "robustness_analysis": "Sensitivity analysis: The col...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Core principle: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works.
math-001800
Linear Algebra: Matrix Multiplication — Row/Column Rules
1
Try to avoid pattern-matching; explain why: Compute $A\mathbf{v}$ in two ways: (i) row-by-column, (ii) as a linear combination of columns. Then explain why both match: Compute $A\mathbf{v}$ and interpret the result as a linear combination of columns. $$A=\begin{pmatrix}7&-23\\-23&-19\end{pmatrix},\qquad \mathbf{v}=\beg...
[ { "method_name": "Column Combination", "approach": "Matrix-vector multiplication equals $x$ times the first column plus $y$ times the second column.", "steps": [ "Step 1: Columns are $\\mathbf{a}_1=\\begin{pmatrix}7\\\\-23\\end{pmatrix}$ and $\\mathbf{a}_2=\\begin{pmatrix}-23\\\\-19\\end{pmatrix}$...
{ "consistency_check": "Consistency verification shows both paths yield the identical boxed result. Final answer: $\\boxed{\\begin{pmatrix}$.\nRow-by-column multiplication and column-combination multiplication are equivalent definitions of $A\\mathbf{v}$. Both yield $(585,915)^T$ here.", "robustness_analysis": "Sen...
[ { "error_description": "Did entrywise (Hadamard) multiplication.", "why_plausible": "Elementwise multiplication is familiar from vectors.", "why_wrong": "Matrix-vector multiplication is defined via dot products/linear combinations; entrywise multiplication does not represent a linear map $\\mathbb{R}^2\...
Remember: Think of $A\mathbf{v}$ as a linear combination of columns of $A$ with weights from $\mathbf{v}$; this interpretation explains why the computational dot-product rule works. (Here the result is $\boxed{\begin{pmatrix}$.)