answer
string
choices
dict
id
string
kind
string
lang
string
question
string
steps
list
subject
string
text
string
topic
string
The value is 56.
{ "A": "54", "B": "58", "C": "56", "D": "60" }
mat_0451
multiple_choice
en
Compute N² + N for N = 7.
[ "7² + 7.", "Value = 56.", "Select option C." ]
math
Answer: 56 Steps: 1. 7² + 7. 2. Value = 56. 3. Select option C. Answer: (C)
proofs
f'(3) = 20.
null
mat_0452
worked_example
cs
Pro f(x) = 3x² + 2x spočítej f'(3) krok za krokem.
[ "f'(x) = 6x + 2.", "Dosaď x = 3.", "6×3 + 2 = 20." ]
math
Answer: f'(3) = 20. Steps: 1. f'(x) = 6x + 2. 2. Dosaď x = 3. 3. 6×3 + 2 = 20.
calculus
A projection drops a vector onto a subspace along perpendiculars, finding the closest point.
null
mat_0453
concept
en
What is a projection?
[ "A projection drops a vector onto a subspace along perpendiculars, finding the closest point.", "So the answer stands: A projection drops a vector onto a subspace along perpendiculars, finding the closest point." ]
math
Answer: A projection drops a vector onto a subspace along perpendiculars, finding the closest point. Steps: 1. A projection drops a vector onto a subspace along perpendiculars, finding the closest point. 2. So the answer stands: A projection drops a vector onto a subspace along perpendiculars, finding the closest point...
linear_algebra
P = 1/7.
null
mat_0454
worked_example
cs
Hází se férovou 7-stěnnou kostkou. Ukaž P(jedno konkrétní číslo).
[ "Příznivé: 1.", "Možné: 7.", "P = 1/7." ]
math
Answer: P = 1/7. Steps: 1. Příznivé: 1. 2. Možné: 7. 3. P = 1/7.
probability
NSD je 9.
{ "A": "6", "B": "9", "C": "12", "D": "15" }
mat_0455
multiple_choice
cs
Najdi největšího společného dělitele NSD(18, 27).
[ "Vytkni 3 dvakrát.", "NSD = 9.", "Vyber možnost B." ]
math
Answer: 9 Steps: 1. Vytkni 3 dvakrát. 2. NSD = 9. 3. Vyber možnost B. Answer: (B)
number_theory
Počítá podmnožiny velikosti r z n objektů.
null
mat_0456
concept
cs
Co je kombinační číslo?
[ "Počítá podmnožiny velikosti r z n objektů.", "Odpověď tedy platí: Počítá podmnožiny velikosti r z n objektů." ]
math
Answer: Počítá podmnožiny velikosti r z n objektů. Steps: 1. Počítá podmnožiny velikosti r z n objektů. 2. Odpověď tedy platí: Počítá podmnožiny velikosti r z n objektů.
combinatorics
An if-and-only-if proof shows both directions, proving P gives Q and Q gives P separately.
null
mat_0457
concept
en
What is a biconditional proof?
[ "An if-and-only-if proof shows both directions, proving P gives Q and Q gives P separately.", "So the answer stands: An if-and-only-if proof shows both directions, proving P gives Q and Q gives P separately." ]
math
Answer: An if-and-only-if proof shows both directions, proving P gives Q and Q gives P separately. Steps: 1. An if-and-only-if proof shows both directions, proving P gives Q and Q gives P separately. 2. So the answer stands: An if-and-only-if proof shows both directions, proving P gives Q and Q gives P separately.
proofs
The integral is 125.
{ "A": "125", "B": "120", "C": "130", "D": "135" }
mat_0458
multiple_choice
en
Compute the integral of 3x² from 0 to 5.
[ "Antiderivative x³.", "5³ = 125.", "Select option A." ]
math
Answer: 125 Steps: 1. Antiderivative x³. 2. 5³ = 125. 3. Select option A. Answer: (A)
calculus
The dot product is 32.
{ "A": "28", "B": "32", "C": "36", "D": "40" }
mat_0459
multiple_choice
en
Find the dot product (4,5) · (3,4).
[ "4×3 + 5×4.", "Product = 32.", "Select option B." ]
math
Answer: 32 Steps: 1. 4×3 + 5×4. 2. Product = 32. 3. Select option B. Answer: (B)
linear_algebra
P(red) = 10/14.
null
mat_0460
worked_example
en
A bag holds 10 red and 4 blue marbles. Show P(red).
[ "Red: 10.", "Total: 14.", "P = 10/14." ]
math
Answer: P(red) = 10/14. Steps: 1. Red: 10. 2. Total: 14. 3. P = 10/14.
probability
gcd = 18.
null
mat_0461
worked_example
en
Compute gcd(36, 54) step by step.
[ "Factor: 36=4×9, 54=6×9.", "Common: 9×gcd(4,6).", "= 9×2 = 18." ]
math
Answer: gcd = 18. Steps: 1. Factor: 36=4×9, 54=6×9. 2. Common: 9×gcd(4,6). 3. = 9×2 = 18.
number_theory
C(5,2) je 10.
{ "A": "5", "B": "10", "C": "15", "D": "20" }
mat_0462
multiple_choice
cs
Vypočítej kombinační číslo C(5,2).
[ "5×4/2.", "= 10.", "Vyber možnost B." ]
math
Answer: 10 Steps: 1. 5×4/2. 2. = 10. 3. Vyber možnost B. Answer: (B)
combinatorics
Sum: 105.
null
mat_0463
worked_example
en
Prove by formula: find the sum 1 + 2 + ... + 14.
[ "Pair 1+14, 2+13, ...", "Use 14×15/2.", "= 105." ]
math
Answer: Sum: 105. Steps: 1. Pair 1+14, 2+13, ... 2. Use 14×15/2. 3. = 105.
proofs
f'(2) = 18.
null
mat_0464
worked_example
en
For f(x) = 2x² + 10x, compute f'(2) step by step.
[ "f'(x) = 4x + 10.", "Plug x = 2.", "4×2 + 10 = 18." ]
math
Answer: f'(2) = 18. Steps: 1. f'(x) = 4x + 10. 2. Plug x = 2. 3. 4×2 + 10 = 18.
calculus
Skalární součin je 11.
{ "A": "7", "B": "15", "C": "11", "D": "19" }
mat_0465
multiple_choice
cs
Najdi skalární součin (1,2) · (3,4).
[ "1×3 + 2×4.", "Součin = 11.", "Vyber možnost C." ]
math
Answer: 11 Steps: 1. 1×3 + 2×4. 2. Součin = 11. 3. Vyber možnost C. Answer: (C)
linear_algebra
P = 1/14.
null
mat_0466
worked_example
en
A fair 14-sided die is rolled. Show P(one specific number).
[ "Favourable: 1.", "Possible: 14.", "P = 1/14." ]
math
Answer: P = 1/14. Steps: 1. Favourable: 1. 2. Possible: 14. 3. P = 1/14.
probability
NSN = 56.
null
mat_0467
worked_example
cs
Spočítej NSN(7, 8) krok za krokem.
[ "NSD(7,8) = 1.", "7×8/1.", "= 56." ]
math
Answer: NSN = 56. Steps: 1. NSD(7,8) = 1. 2. 7×8/1. 3. = 56.
number_theory
It approximates n! via roots and powers, taming huge factorials asymptotically.
null
mat_0468
concept
en
What is Stirling's formula?
[ "It approximates n! via roots and powers, taming huge factorials asymptotically.", "So the answer stands: It approximates n! via roots and powers, taming huge factorials asymptotically." ]
math
Answer: It approximates n! via roots and powers, taming huge factorials asymptotically. Steps: 1. It approximates n! via roots and powers, taming huge factorials asymptotically. 2. So the answer stands: It approximates n! via roots and powers, taming huge factorials asymptotically.
combinatorics
Half: 55, so 110 is even.
null
mat_0469
worked_example
en
Show N² + N is even for N = 10 by computing its half.
[ "10² + 10 = 110.", "110 / 2 = 55.", "Integer, so even." ]
math
Answer: Half: 55, so 110 is even. Steps: 1. 10² + 10 = 110. 2. 110 / 2 = 55. 3. Integer, so even.
proofs
Integral: 1728.
null
mat_0470
worked_example
en
Evaluate the integral of 3x² from 0 to 12.
[ "Antiderivative: x³.", "Evaluate 0 to 12.", "12³ − 0 = 1728." ]
math
Answer: Integral: 1728. Steps: 1. Antiderivative: x³. 2. Evaluate 0 to 12. 3. 12³ − 0 = 1728.
calculus
Least squares fits lines by minimizing squared error, solving unsolvable systems approximately.
null
mat_0471
concept
en
Why least squares?
[ "Least squares fits lines by minimizing squared error, solving unsolvable systems approximately.", "So the answer stands: Least squares fits lines by minimizing squared error, solving unsolvable systems approximately." ]
math
Answer: Least squares fits lines by minimizing squared error, solving unsolvable systems approximately. Steps: 1. Least squares fits lines by minimizing squared error, solving unsolvable systems approximately. 2. So the answer stands: Least squares fits lines by minimizing squared error, solving unsolvable systems appr...
linear_algebra
The answer is p-value.
{ "A": "Coin age", "B": "Shoe size", "C": "Star sign", "D": "p-value" }
mat_0472
multiple_choice
en
Choose: what scores extreme data?
[ "Small casts doubt.", "So: p-value.", "Select option D." ]
math
Answer: p-value Steps: 1. Small casts doubt. 2. So: p-value. 3. Select option D. Answer: (D)
probability
Remainder: 1.
null
mat_0473
worked_example
en
Compute (127) mod 7.
[ "Divide 127 by 7.", "7×18 = 126.", "127 − 126 = 1." ]
math
Answer: Remainder: 1. Steps: 1. Divide 127 by 7. 2. 7×18 = 126. 3. 127 − 126 = 1.
number_theory
C(14,3) = 364.
null
mat_0474
worked_example
en
Show the computation of C(14,3).
[ "n(n−1)(n−2)/6.", "14×13×12/6.", "= 364." ]
math
Answer: C(14,3) = 364. Steps: 1. n(n−1)(n−2)/6. 2. 14×13×12/6. 3. = 364.
combinatorics
The answer is And/or quantifiers.
{ "A": "Numbers only", "B": "Names only", "C": "Nothing ever", "D": "And/or quantifiers" }
mat_0475
multiple_choice
en
Choose: what flips under negation?
[ "De Morgan rules it.", "So: And/or quantifiers.", "Select option D." ]
math
Answer: And/or quantifiers Steps: 1. De Morgan rules it. 2. So: And/or quantifiers. 3. Select option D. Answer: (D)
proofs
Integrál: 64.
null
mat_0476
worked_example
cs
Vyčísli integrál 3x² od 0 do 4.
[ "Primitivní: x³.", "Vyčísli 0 až 4.", "4³ − 0 = 64." ]
math
Answer: Integrál: 64. Steps: 1. Primitivní: x³. 2. Vyčísli 0 až 4. 3. 4³ − 0 = 64.
calculus
Determinant: 130.
null
mat_0477
worked_example
en
Compute det [[11,1],[2,12]] step by step.
[ "ad − bc.", "11×12 − 1×2.", "= 130." ]
math
Answer: Determinant: 130. Steps: 1. ad − bc. 2. 11×12 − 1×2. 3. = 130.
linear_algebra
E = 7.
null
mat_0478
worked_example
en
Compute E of a uniform draw from {1..13}.
[ "Mean of 1..13.", "(13+1)/2.", "E = 7." ]
math
Answer: E = 7. Steps: 1. Mean of 1..13. 2. (13+1)/2. 3. E = 7.
probability
Zbytek je 8.
{ "A": "0", "B": "1", "C": "8", "D": "2" }
mat_0479
multiple_choice
cs
Vypočítej (107) mod 9.
[ "107 ÷ 9.", "Zbytek 8.", "Vyber možnost C." ]
math
Answer: 8 Steps: 1. 107 ÷ 9. 2. Zbytek 8. 3. Vyber možnost C. Answer: (C)
number_theory
P(5,3) = 60.
null
mat_0480
worked_example
cs
Ukaž výpočet P(5,3).
[ "n(n−1)(n−2).", "5×4×3.", "= 60." ]
math
Answer: P(5,3) = 60. Steps: 1. n(n−1)(n−2). 2. 5×4×3. 3. = 60.
combinatorics
Polovina: 10, číslo 20 je sudé.
null
mat_0481
worked_example
cs
Ukaž, že N² + N je sudé pro N = 4, výpočtem poloviny.
[ "4² + 4 = 20.", "20 / 2 = 10.", "Celé číslo, tedy sudé." ]
math
Answer: Polovina: 10, číslo 20 je sudé. Steps: 1. 4² + 4 = 20. 2. 20 / 2 = 10. 3. Celé číslo, tedy sudé.
proofs
Limita: 8.
null
mat_0482
worked_example
cs
Vyčísli limitu (x² − 4²)/(x − 4) pro x → 4.
[ "Rozlož: (x−4)(x+4).", "Pokrať (x−4).", "Dosaď 4: 4+4 = 8." ]
math
Answer: Limita: 8. Steps: 1. Rozlož: (x−4)(x+4). 2. Pokrať (x−4). 3. Dosaď 4: 4+4 = 8.
calculus
The answer is Eigenvector.
{ "A": "Random vector", "B": "Zero vector", "C": "Eigenvector", "D": "Long vector" }
mat_0483
multiple_choice
en
Choose: what keeps direction?
[ "Scaled by eigenvalue.", "So: Eigenvector.", "Select option C." ]
math
Answer: Eigenvector Steps: 1. Scaled by eigenvalue. 2. So: Eigenvector. 3. Select option C. Answer: (C)
linear_algebra
Covariance measures joint variation of two variables, positive when they rise together.
null
mat_0484
concept
en
What is covariance?
[ "Covariance measures joint variation of two variables, positive when they rise together.", "So the answer stands: Covariance measures joint variation of two variables, positive when they rise together." ]
math
Answer: Covariance measures joint variation of two variables, positive when they rise together. Steps: 1. Covariance measures joint variation of two variables, positive when they rise together. 2. So the answer stands: Covariance measures joint variation of two variables, positive when they rise together.
probability
They tell which numbers are squares mod p, decided fast by Euler's criterion.
null
mat_0485
concept
en
Why quadratic residues?
[ "They tell which numbers are squares mod p, decided fast by Euler's criterion.", "So the answer stands: They tell which numbers are squares mod p, decided fast by Euler's criterion." ]
math
Answer: They tell which numbers are squares mod p, decided fast by Euler's criterion. Steps: 1. They tell which numbers are squares mod p, decided fast by Euler's criterion. 2. So the answer stands: They tell which numbers are squares mod p, decided fast by Euler's criterion.
number_theory
P(4,2) je 12.
{ "A": "8", "B": "16", "C": "12", "D": "20" }
mat_0486
multiple_choice
cs
Vypočítej permutační číslo P(4,2).
[ "4×3.", "= 12.", "Vyber možnost C." ]
math
Answer: 12 Steps: 1. 4×3. 2. = 12. 3. Vyber možnost C. Answer: (C)
combinatorics
Řádků: 32.
null
mat_0487
worked_example
cs
Důkaz prochází všechny případy 5 booleovských proměnných. Kolik řádků?
[ "2 volby každá.", "2^5 = 32." ]
math
Answer: Řádků: 32. Steps: 1. 2 volby každá. 2. 2^5 = 32.
proofs
Inflection points mark where bending flips, revealing structural changes in the graph.
null
mat_0488
concept
en
Why find inflection points?
[ "Inflection points mark where bending flips, revealing structural changes in the graph.", "So the answer stands: Inflection points mark where bending flips, revealing structural changes in the graph." ]
math
Answer: Inflection points mark where bending flips, revealing structural changes in the graph. Steps: 1. Inflection points mark where bending flips, revealing structural changes in the graph. 2. So the answer stands: Inflection points mark where bending flips, revealing structural changes in the graph.
calculus
Trace: 25.
null
mat_0489
worked_example
en
Compute the trace of [[12,0],[0,13]].
[ "Sum diagonal.", "12 + 13.", "= 25." ]
math
Answer: Trace: 25. Steps: 1. Sum diagonal. 2. 12 + 13. 3. = 25.
linear_algebra
Correlation scales covariance to [-1,1], giving a universal strength of linear relation.
null
mat_0490
concept
en
Why correlation?
[ "Correlation scales covariance to [-1,1], giving a universal strength of linear relation.", "So the answer stands: Correlation scales covariance to [-1,1], giving a universal strength of linear relation." ]
math
Answer: Correlation scales covariance to [-1,1], giving a universal strength of linear relation. Steps: 1. Correlation scales covariance to [-1,1], giving a universal strength of linear relation. 2. So the answer stands: Correlation scales covariance to [-1,1], giving a universal strength of linear relation.
probability
The gcd is 18.
{ "A": "18", "B": "15", "C": "21", "D": "24" }
mat_0491
multiple_choice
en
Find gcd(36, 54).
[ "Factor 3 out twice.", "gcd = 18.", "Select option A." ]
math
Answer: 18 Steps: 1. Factor 3 out twice. 2. gcd = 18. 3. Select option A. Answer: (A)
number_theory
C(14,2) = 91.
null
mat_0492
worked_example
en
Show the computation of C(14,2).
[ "Formula n(n−1)/2.", "14×13/2.", "= 91." ]
math
Answer: C(14,2) = 91. Steps: 1. Formula n(n−1)/2. 2. 14×13/2. 3. = 91.
combinatorics
Rows: 2048.
null
mat_0493
worked_example
en
A proof checks all cases of 11 boolean variables. How many rows?
[ "2 choices each.", "2^11 = 2048." ]
math
Answer: Rows: 2048. Steps: 1. 2 choices each. 2. 2^11 = 2048.
proofs
Limit: 24.
null
mat_0494
worked_example
en
Evaluate the limit of (x² − 12²)/(x − 12) as x → 12.
[ "Factor: (x−12)(x+12).", "Cancel (x−12).", "Plug 12: 12+12 = 24." ]
math
Answer: Limit: 24. Steps: 1. Factor: (x−12)(x+12). 2. Cancel (x−12). 3. Plug 12: 12+12 = 24.
calculus
The null space holds all vectors mapped to zero, measuring how much the map collapses.
null
mat_0495
concept
en
What is the null space?
[ "The null space holds all vectors mapped to zero, measuring how much the map collapses.", "So the answer stands: The null space holds all vectors mapped to zero, measuring how much the map collapses." ]
math
Answer: The null space holds all vectors mapped to zero, measuring how much the map collapses. Steps: 1. The null space holds all vectors mapped to zero, measuring how much the map collapses. 2. So the answer stands: The null space holds all vectors mapped to zero, measuring how much the map collapses.
linear_algebra
Odpověď je prostor výsledků.
{ "A": "seznam přání", "B": "pytel hádání", "C": "truhla nadějí", "D": "prostor výsledků" }
mat_0496
multiple_choice
cs
Vyber: co vypisuje všechny výsledky?
[ "Jevy jsou podmnožiny.", "Tedy: prostor výsledků.", "Vyber možnost D." ]
math
Answer: prostor výsledků Steps: 1. Jevy jsou podmnožiny. 2. Tedy: prostor výsledků. 3. Vyber možnost D. Answer: (D)
probability
lcm = 24.
null
mat_0497
worked_example
en
Compute lcm(12, 8) step by step.
[ "gcd(12,8) = 4.", "12×8/4.", "= 24." ]
math
Answer: lcm = 24. Steps: 1. gcd(12,8) = 4. 2. 12×8/4. 3. = 24.
number_theory
The answer is Pigeonhole.
{ "A": "Big boxes", "B": "Few items", "C": "Pigeonhole", "D": "Kind hosts" }
mat_0498
multiple_choice
en
Choose: what forces sharing?
[ "Items exceed boxes.", "So: Pigeonhole.", "Select option C." ]
math
Answer: Pigeonhole Steps: 1. Items exceed boxes. 2. So: Pigeonhole. 3. Select option C. Answer: (C)
combinatorics
Sum: 120.
null
mat_0499
worked_example
en
Prove by formula: find the sum 1 + 2 + ... + 15.
[ "Pair 1+15, 2+14, ...", "Use 15×16/2.", "= 120." ]
math
Answer: Sum: 120. Steps: 1. Pair 1+15, 2+14, ... 2. Use 15×16/2. 3. = 120.
proofs
The limit is 10.
{ "A": "8", "B": "10", "C": "12", "D": "14" }
mat_0500
multiple_choice
en
Find the limit of (x² − 5²)/(x − 5) as x → 5.
[ "Factor (x−5)(x+5).", "Cancel, get 2×5 = 10.", "Select option B." ]
math
Answer: 10 Steps: 1. Factor (x−5)(x+5). 2. Cancel, get 2×5 = 10. 3. Select option B. Answer: (B)
calculus
The answer is Trace.
{ "A": "Rank", "B": "Norm", "C": "Size", "D": "Trace" }
mat_0501
multiple_choice
en
Choose: what sums the diagonal?
[ "Eigenvalue sum equal.", "So: Trace.", "Select option D." ]
math
Answer: Trace Steps: 1. Eigenvalue sum equal. 2. So: Trace. 3. Select option D. Answer: (D)
linear_algebra
It jumps between states with fixed probabilities depending only on the current state.
null
mat_0502
concept
en
What is a Markov chain?
[ "It jumps between states with fixed probabilities depending only on the current state.", "So the answer stands: It jumps between states with fixed probabilities depending only on the current state." ]
math
Answer: It jumps between states with fixed probabilities depending only on the current state. Steps: 1. It jumps between states with fixed probabilities depending only on the current state. 2. So the answer stands: It jumps between states with fixed probabilities depending only on the current state.
probability
It encodes residue status as 1, -1, or 0, compressing square questions to algebra.
null
mat_0503
concept
en
What is Legendre's symbol?
[ "It encodes residue status as 1, -1, or 0, compressing square questions to algebra.", "So the answer stands: It encodes residue status as 1, -1, or 0, compressing square questions to algebra." ]
math
Answer: It encodes residue status as 1, -1, or 0, compressing square questions to algebra. Steps: 1. It encodes residue status as 1, -1, or 0, compressing square questions to algebra. 2. So the answer stands: It encodes residue status as 1, -1, or 0, compressing square questions to algebra.
number_theory
The answer is Gray code.
{ "A": "Wild order", "B": "Blind list", "C": "Vague chain", "D": "Gray code" }
mat_0504
multiple_choice
en
Choose: what orders flipping one bit?
[ "Neighbours differ once.", "So: Gray code.", "Select option D." ]
math
Answer: Gray code Steps: 1. Neighbours differ once. 2. So: Gray code. 3. Select option D. Answer: (D)
combinatorics
The answer is Assuming conclusion.
{ "A": "Assuming conclusion", "B": "Round diagrams", "C": "Long proofs", "D": "Many cases" }
mat_0505
multiple_choice
en
Choose: what is circular reasoning?
[ "Proves nothing at all.", "So: Assuming conclusion.", "Select option A." ]
math
Answer: Assuming conclusion Steps: 1. Proves nothing at all. 2. So: Assuming conclusion. 3. Select option A. Answer: (A)
proofs
f'(4) = 35.
null
mat_0506
worked_example
cs
Pro f(x) = 4x² + 3x spočítej f'(4) krok za krokem.
[ "f'(x) = 8x + 3.", "Dosaď x = 4.", "8×4 + 3 = 35." ]
math
Answer: f'(4) = 35. Steps: 1. f'(x) = 8x + 3. 2. Dosaď x = 4. 3. 8×4 + 3 = 35.
calculus
Odpověď je nenulový determinant.
{ "A": "velké prvky", "B": "kulatý tvar", "C": "dlouhé jméno", "D": "nenulový determinant" }
mat_0507
multiple_choice
cs
Vyber: co detekuje regularitu?
[ "Nula znamená zhroucení.", "Tedy: nenulový determinant.", "Vyber možnost D." ]
math
Answer: nenulový determinant Steps: 1. Nula znamená zhroucení. 2. Tedy: nenulový determinant. 3. Vyber možnost D. Answer: (D)
linear_algebra
They give long-run state fractions, predicting where chains settle over time.
null
mat_0508
concept
en
Why stationary distributions?
[ "They give long-run state fractions, predicting where chains settle over time.", "So the answer stands: They give long-run state fractions, predicting where chains settle over time." ]
math
Answer: They give long-run state fractions, predicting where chains settle over time. Steps: 1. They give long-run state fractions, predicting where chains settle over time. 2. So the answer stands: They give long-run state fractions, predicting where chains settle over time.
probability
Největší společný dělitel je největší číslo dělící obě čísla.
null
mat_0509
concept
cs
Co je NSD?
[ "Největší společný dělitel je největší číslo dělící obě čísla.", "Odpověď tedy platí: Největší společný dělitel je největší číslo dělící obě čísla." ]
math
Answer: Největší společný dělitel je největší číslo dělící obě čísla. Steps: 1. Největší společný dělitel je největší číslo dělící obě čísla. 2. Odpověď tedy platí: Největší společný dělitel je největší číslo dělící obě čísla.
number_theory
Counting one set two ways proves identities, a favourite elegant technique.
null
mat_0510
concept
en
Why double counting?
[ "Counting one set two ways proves identities, a favourite elegant technique.", "So the answer stands: Counting one set two ways proves identities, a favourite elegant technique." ]
math
Answer: Counting one set two ways proves identities, a favourite elegant technique. Steps: 1. Counting one set two ways proves identities, a favourite elegant technique. 2. So the answer stands: Counting one set two ways proves identities, a favourite elegant technique.
combinatorics
Venn diagrams picture set relations, guiding proofs about unions, intersections, and complements.
null
mat_0511
concept
en
Why use Venn diagrams?
[ "Venn diagrams picture set relations, guiding proofs about unions, intersections, and complements.", "So the answer stands: Venn diagrams picture set relations, guiding proofs about unions, intersections, and complements." ]
math
Answer: Venn diagrams picture set relations, guiding proofs about unions, intersections, and complements. Steps: 1. Venn diagrams picture set relations, guiding proofs about unions, intersections, and complements. 2. So the answer stands: Venn diagrams picture set relations, guiding proofs about unions, intersections, ...
proofs
The answer is Fundamental theorem.
{ "A": "Guessing rule", "B": "Lucky axiom", "C": "Fundamental theorem", "D": "Long division" }
mat_0512
multiple_choice
en
Choose: what links both operations?
[ "Integrals via antiderivatives.", "So: Fundamental theorem.", "Select option C." ]
math
Answer: Fundamental theorem Steps: 1. Integrals via antiderivatives. 2. So: Fundamental theorem. 3. Select option C. Answer: (C)
calculus
Rank plus nullity equals columns, linking image size to collapse in one equation.
null
mat_0513
concept
en
Why rank-nullity?
[ "Rank plus nullity equals columns, linking image size to collapse in one equation.", "So the answer stands: Rank plus nullity equals columns, linking image size to collapse in one equation." ]
math
Answer: Rank plus nullity equals columns, linking image size to collapse in one equation. Steps: 1. Rank plus nullity equals columns, linking image size to collapse in one equation. 2. So the answer stands: Rank plus nullity equals columns, linking image size to collapse in one equation.
linear_algebra
Odpověď je rozptyl.
{ "A": "rozptyl", "B": "průměr", "C": "modus", "D": "naděje" }
mat_0514
multiple_choice
cs
Vyber: co měří rozptyl?
[ "Čtvercové odchylky průměrovány.", "Tedy: rozptyl.", "Vyber možnost A." ]
math
Answer: rozptyl Steps: 1. Čtvercové odchylky průměrovány. 2. Tedy: rozptyl. 3. Vyber možnost A. Answer: (A)
probability
It swaps primes in Legendre symbols, making huge residue questions computable.
null
mat_0515
concept
en
Why quadratic reciprocity?
[ "It swaps primes in Legendre symbols, making huge residue questions computable.", "So the answer stands: It swaps primes in Legendre symbols, making huge residue questions computable." ]
math
Answer: It swaps primes in Legendre symbols, making huge residue questions computable. Steps: 1. It swaps primes in Legendre symbols, making huge residue questions computable. 2. So the answer stands: It swaps primes in Legendre symbols, making huge residue questions computable.
number_theory
A bijection pairs sets one-to-one, proving equal size without any counting.
null
mat_0516
concept
en
What is a bijection?
[ "A bijection pairs sets one-to-one, proving equal size without any counting.", "So the answer stands: A bijection pairs sets one-to-one, proving equal size without any counting." ]
math
Answer: A bijection pairs sets one-to-one, proving equal size without any counting. Steps: 1. A bijection pairs sets one-to-one, proving equal size without any counting. 2. So the answer stands: A bijection pairs sets one-to-one, proving equal size without any counting.
combinatorics
Lemma je malé pomocné tvrzení, jež dělí důkaz na kontrolovatelné kroky.
null
mat_0517
concept
cs
Co je lemma?
[ "Lemma je malé pomocné tvrzení, jež dělí důkaz na kontrolovatelné kroky.", "Odpověď tedy platí: Lemma je malé pomocné tvrzení, jež dělí důkaz na kontrolovatelné kroky." ]
math
Answer: Lemma je malé pomocné tvrzení, jež dělí důkaz na kontrolovatelné kroky. Steps: 1. Lemma je malé pomocné tvrzení, jež dělí důkaz na kontrolovatelné kroky. 2. Odpověď tedy platí: Lemma je malé pomocné tvrzení, jež dělí důkaz na kontrolovatelné kroky.
proofs
f'(3) = 29.
null
mat_0518
worked_example
en
For f(x) = 3x² + 11x, compute f'(3) step by step.
[ "f'(x) = 6x + 11.", "Plug x = 3.", "6×3 + 11 = 29." ]
math
Answer: f'(3) = 29. Steps: 1. f'(x) = 6x + 11. 2. Plug x = 3. 3. 6×3 + 11 = 29.
calculus
A linear system is equations linear in unknowns, solved together by elimination.
null
mat_0519
concept
en
What is a linear system?
[ "A linear system is equations linear in unknowns, solved together by elimination.", "So the answer stands: A linear system is equations linear in unknowns, solved together by elimination." ]
math
Answer: A linear system is equations linear in unknowns, solved together by elimination. Steps: 1. A linear system is equations linear in unknowns, solved together by elimination. 2. So the answer stands: A linear system is equations linear in unknowns, solved together by elimination.
linear_algebra
Pravděpodobnost je 1/7.
{ "A": "1/6", "B": "1/7", "C": "1/8", "D": "2/7" }
mat_0520
multiple_choice
cs
Hází se férovou 7-stěnnou kostkou. Jaká je pravděpodobnost jednoho konkrétního čísla?
[ "1 stěna z 7.", "P = 1/7.", "Vyber možnost B." ]
math
Answer: 1/7 Steps: 1. 1 stěna z 7. 2. P = 1/7. 3. Vyber možnost B. Answer: (B)
probability
gcd = 20.
null
mat_0521
worked_example
en
Compute gcd(40, 60) step by step.
[ "Factor: 40=4×10, 60=6×10.", "Common: 10×gcd(4,6).", "= 10×2 = 20." ]
math
Answer: gcd = 20. Steps: 1. Factor: 40=4×10, 60=6×10. 2. Common: 10×gcd(4,6). 3. = 10×2 = 20.
number_theory
C(8,2) is 28.
{ "A": "28", "B": "20", "C": "36", "D": "44" }
mat_0522
multiple_choice
en
Compute C(8,2).
[ "8×7/2.", "= 28.", "Select option A." ]
math
Answer: 28 Steps: 1. 8×7/2. 2. = 28. 3. Select option A. Answer: (A)
combinatorics
Součet: 45.
null
mat_0523
worked_example
cs
Dokaž vzorcem: najdi součet 1 + 2 + ... + 9.
[ "Páruj 1+9, 2+8, ...", "Použij 9×10/2.", "= 45." ]
math
Answer: Součet: 45. Steps: 1. Páruj 1+9, 2+8, ... 2. Použij 9×10/2. 3. = 45.
proofs
A partial derivative varies one variable while freezing others, extending calculus to surfaces.
null
mat_0524
concept
en
What is a partial derivative?
[ "A partial derivative varies one variable while freezing others, extending calculus to surfaces.", "So the answer stands: A partial derivative varies one variable while freezing others, extending calculus to surfaces." ]
math
Answer: A partial derivative varies one variable while freezing others, extending calculus to surfaces. Steps: 1. A partial derivative varies one variable while freezing others, extending calculus to surfaces. 2. So the answer stands: A partial derivative varies one variable while freezing others, extending calculus to...
calculus
Inverzní matice ruší původní zobrazení a existuje při nenulovém determinantu.
null
mat_0525
concept
cs
Co je inverzní matice?
[ "Inverzní matice ruší původní zobrazení a existuje při nenulovém determinantu.", "Odpověď tedy platí: Inverzní matice ruší původní zobrazení a existuje při nenulovém determinantu." ]
math
Answer: Inverzní matice ruší původní zobrazení a existuje při nenulovém determinantu. Steps: 1. Inverzní matice ruší původní zobrazení a existuje při nenulovém determinantu. 2. Odpověď tedy platí: Inverzní matice ruší původní zobrazení a existuje při nenulovém determinantu.
linear_algebra
It counts rare events in fixed intervals, modelling arrivals and decays.
null
mat_0526
concept
en
What is the Poisson distribution?
[ "It counts rare events in fixed intervals, modelling arrivals and decays.", "So the answer stands: It counts rare events in fixed intervals, modelling arrivals and decays." ]
math
Answer: It counts rare events in fixed intervals, modelling arrivals and decays. Steps: 1. It counts rare events in fixed intervals, modelling arrivals and decays. 2. So the answer stands: It counts rare events in fixed intervals, modelling arrivals and decays.
probability
NSD = 10.
null
mat_0527
worked_example
cs
Spočítej NSD(20, 30) krok za krokem.
[ "Rozlož: 20=4×5, 30=6×5.", "Společné: 5×NSD(4,6).", "= 5×2 = 10." ]
math
Answer: NSD = 10. Steps: 1. Rozlož: 20=4×5, 30=6×5. 2. Společné: 5×NSD(4,6). 3. = 5×2 = 10.
number_theory
P(13,3) = 1716.
null
mat_0528
worked_example
en
Show the computation of P(13,3).
[ "n(n−1)(n−2).", "13×12×11.", "= 1716." ]
math
Answer: P(13,3) = 1716. Steps: 1. n(n−1)(n−2). 2. 13×12×11. 3. = 1716.
combinatorics
The table has 128 rows.
{ "A": "126", "B": "128", "C": "130", "D": "132" }
mat_0529
multiple_choice
en
How many rows does a truth table with 7 variables have?
[ "2^7 rows.", "Total: 128.", "Select option B." ]
math
Answer: 128 Steps: 1. 2^7 rows. 2. Total: 128. 3. Select option B. Answer: (B)
proofs
Základní věta spojuje derivace a integrály přes primitivní funkce.
null
mat_0530
concept
cs
Co je základní věta kalkulu?
[ "Základní věta spojuje derivace a integrály přes primitivní funkce.", "Odpověď tedy platí: Základní věta spojuje derivace a integrály přes primitivní funkce." ]
math
Answer: Základní věta spojuje derivace a integrály přes primitivní funkce. Steps: 1. Základní věta spojuje derivace a integrály přes primitivní funkce. 2. Odpověď tedy platí: Základní věta spojuje derivace a integrály přes primitivní funkce.
calculus
The determinant is 34.
{ "A": "34", "B": "31", "C": "37", "D": "40" }
mat_0531
multiple_choice
en
Find the determinant of [[5,2],[3,8]].
[ "5×8 − 2×3.", "Det = 34.", "Select option A." ]
math
Answer: 34 Steps: 1. 5×8 − 2×3. 2. Det = 34. 3. Select option A. Answer: (A)
linear_algebra
Střední hodnota je 3.
{ "A": "4", "B": "2", "C": "3", "D": "5" }
mat_0532
multiple_choice
cs
Najdi střední hodnotu rovnoměrného tahu z {1..5}.
[ "(5+1)/2.", "E = 3.", "Vyber možnost C." ]
math
Answer: 3 Steps: 1. (5+1)/2. 2. E = 3. 3. Vyber možnost C. Answer: (C)
probability
NSN je 30.
{ "A": "28", "B": "32", "C": "34", "D": "30" }
mat_0533
multiple_choice
cs
Najdi nejmenší společný násobek NSN(5, 6).
[ "5×6/NSD.", "NSN = 30.", "Vyber možnost D." ]
math
Answer: 30 Steps: 1. 5×6/NSD. 2. NSN = 30. 3. Vyber možnost D. Answer: (D)
number_theory
P(7,2) is 42.
{ "A": "35", "B": "42", "C": "49", "D": "56" }
mat_0534
multiple_choice
en
Compute P(7,2).
[ "7×6.", "= 42.", "Select option B." ]
math
Answer: 42 Steps: 1. 7×6. 2. = 42. 3. Select option B. Answer: (B)
combinatorics
Half: 66, so 132 is even.
null
mat_0535
worked_example
en
Show N² + N is even for N = 11 by computing its half.
[ "11² + 11 = 132.", "132 / 2 = 66.", "Integer, so even." ]
math
Answer: Half: 66, so 132 is even. Steps: 1. 11² + 11 = 132. 2. 132 / 2 = 66. 3. Integer, so even.
proofs
Taylorovy řady aproximují funkce polynomy s odhadem chyby.
null
mat_0536
concept
cs
Proč Taylorovy řady?
[ "Taylorovy řady aproximují funkce polynomy s odhadem chyby.", "Odpověď tedy platí: Taylorovy řady aproximují funkce polynomy s odhadem chyby." ]
math
Answer: Taylorovy řady aproximují funkce polynomy s odhadem chyby. Steps: 1. Taylorovy řady aproximují funkce polynomy s odhadem chyby. 2. Odpověď tedy platí: Taylorovy řady aproximují funkce polynomy s odhadem chyby.
calculus
Dot product: 83.
null
mat_0537
worked_example
en
Compute (11,10) · (3,5) step by step.
[ "Multiply components.", "11×3 + 10×5.", "= 83." ]
math
Answer: Dot product: 83. Steps: 1. Multiply components. 2. 11×3 + 10×5. 3. = 83.
linear_algebra
It models waiting times with no memory, fitting lifetimes and queues.
null
mat_0538
concept
en
Why exponential distribution?
[ "It models waiting times with no memory, fitting lifetimes and queues.", "So the answer stands: It models waiting times with no memory, fitting lifetimes and queues." ]
math
Answer: It models waiting times with no memory, fitting lifetimes and queues. Steps: 1. It models waiting times with no memory, fitting lifetimes and queues. 2. So the answer stands: It models waiting times with no memory, fitting lifetimes and queues.
probability
Remainder: 5.
null
mat_0539
worked_example
en
Compute (138) mod 7.
[ "Divide 138 by 7.", "7×19 = 133.", "138 − 133 = 5." ]
math
Answer: Remainder: 5. Steps: 1. Divide 138 by 7. 2. 7×19 = 133. 3. 138 − 133 = 5.
number_theory
C(15,3) = 455.
null
mat_0540
worked_example
en
Show the computation of C(15,3).
[ "n(n−1)(n−2)/6.", "15×14×13/6.", "= 455." ]
math
Answer: C(15,3) = 455. Steps: 1. n(n−1)(n−2)/6. 2. 15×14×13/6. 3. = 455.
combinatorics
Rows: 4096.
null
mat_0541
worked_example
en
A proof checks all cases of 12 boolean variables. How many rows?
[ "2 choices each.", "2^12 = 4096." ]
math
Answer: Rows: 4096. Steps: 1. 2 choices each. 2. 2^12 = 4096.
proofs
Integral: 2197.
null
mat_0542
worked_example
en
Evaluate the integral of 3x² from 0 to 13.
[ "Antiderivative: x³.", "Evaluate 0 to 13.", "13³ − 0 = 2197." ]
math
Answer: Integral: 2197. Steps: 1. Antiderivative: x³. 2. Evaluate 0 to 13. 3. 13³ − 0 = 2197.
calculus
Augmenting appends answers to coefficients, keeping elimination tidy in one array.
null
mat_0543
concept
en
Why augmented matrices?
[ "Augmenting appends answers to coefficients, keeping elimination tidy in one array.", "So the answer stands: Augmenting appends answers to coefficients, keeping elimination tidy in one array." ]
math
Answer: Augmenting appends answers to coefficients, keeping elimination tidy in one array. Steps: 1. Augmenting appends answers to coefficients, keeping elimination tidy in one array. 2. So the answer stands: Augmenting appends answers to coefficients, keeping elimination tidy in one array.
linear_algebra
P(red) = 11/15.
null
mat_0544
worked_example
en
A bag holds 11 red and 4 blue marbles. Show P(red).
[ "Red: 11.", "Total: 15.", "P = 11/15." ]
math
Answer: P(red) = 11/15. Steps: 1. Red: 11. 2. Total: 15. 3. P = 11/15.
probability
The remainder is 2.
{ "A": "3", "B": "2", "C": "4", "D": "5" }
mat_0545
multiple_choice
en
Find (128) mod 9.
[ "128 ÷ 9.", "Remainder 2.", "Select option B." ]
math
Answer: 2 Steps: 1. 128 ÷ 9. 2. Remainder 2. 3. Select option B. Answer: (B)
number_theory
C(9,3) is 84.
{ "A": "75", "B": "93", "C": "84", "D": "102" }
mat_0546
multiple_choice
en
Compute C(9,3).
[ "9×8×7/6.", "= 84.", "Select option C." ]
math
Answer: 84 Steps: 1. 9×8×7/6. 2. = 84. 3. Select option C. Answer: (C)
combinatorics
De Morgan's laws flip and/or under negation, turning not-(A and B) into (not A) or (not B).
null
mat_0547
concept
en
What is De Morgan's law?
[ "De Morgan's laws flip and/or under negation, turning not-(A and B) into (not A) or (not B).", "So the answer stands: De Morgan's laws flip and/or under negation, turning not-(A and B) into (not A) or (not B)." ]
math
Answer: De Morgan's laws flip and/or under negation, turning not-(A and B) into (not A) or (not B). Steps: 1. De Morgan's laws flip and/or under negation, turning not-(A and B) into (not A) or (not B). 2. So the answer stands: De Morgan's laws flip and/or under negation, turning not-(A and B) into (not A) or (not B).
proofs
The answer is Partial derivative.
{ "A": "Total guess", "B": "Full stop", "C": "Side note", "D": "Partial derivative" }
mat_0548
multiple_choice
en
Choose: what varies one variable?
[ "Others frozen.", "So: Partial derivative.", "Select option D." ]
math
Answer: Partial derivative Steps: 1. Others frozen. 2. So: Partial derivative. 3. Select option D. Answer: (D)
calculus
The trace is 15.
{ "A": "13", "B": "15", "C": "17", "D": "19" }
mat_0549
multiple_choice
en
Find the trace of [[6,1],[2,9]].
[ "6 + 9.", "Trace = 15.", "Select option B." ]
math
Answer: 15 Steps: 1. 6 + 9. 2. Trace = 15. 3. Select option B. Answer: (B)
linear_algebra
Průměry mnoha veličin jsou normální, modeluje chyby a variace.
null
mat_0550
concept
cs
Proč normální rozdělení?
[ "Průměry mnoha veličin jsou normální, modeluje chyby a variace.", "Odpověď tedy platí: Průměry mnoha veličin jsou normální, modeluje chyby a variace." ]
math
Answer: Průměry mnoha veličin jsou normální, modeluje chyby a variace. Steps: 1. Průměry mnoha veličin jsou normální, modeluje chyby a variace. 2. Odpověď tedy platí: Průměry mnoha veličin jsou normální, modeluje chyby a variace.
probability