answer
string
choices
dict
id
string
kind
string
lang
string
question
string
steps
list
subject
string
text
string
topic
string
The value is 20.
{ "A": "18", "B": "22", "C": "24", "D": "20" }
mat_0151
multiple_choice
en
Compute N² + N for N = 4.
[ "4² + 4.", "Value = 20.", "Select option D." ]
math
Answer: 20 Steps: 1. 4² + 4. 2. Value = 20. 3. Select option D. Answer: (D)
proofs
The answer is Taylor series.
{ "A": "Taylor series", "B": "Random dots", "C": "Wild guesses", "D": "Blank lines" }
mat_0152
multiple_choice
en
Choose: what approximates functions?
[ "Polynomials with error bounds.", "So: Taylor series.", "Select option A." ]
math
Answer: Taylor series Steps: 1. Polynomials with error bounds. 2. So: Taylor series. 3. Select option A. Answer: (A)
calculus
An eigenvector keeps its direction under the map, scaled only by its eigenvalue.
null
mat_0153
concept
en
What is an eigenvector?
[ "An eigenvector keeps its direction under the map, scaled only by its eigenvalue.", "So the answer stands: An eigenvector keeps its direction under the map, scaled only by its eigenvalue." ]
math
Answer: An eigenvector keeps its direction under the map, scaled only by its eigenvalue. Steps: 1. An eigenvector keeps its direction under the map, scaled only by its eigenvalue. 2. So the answer stands: An eigenvector keeps its direction under the map, scaled only by its eigenvalue.
linear_algebra
The answer is Variance.
{ "A": "Variance", "B": "Mean", "C": "Mode", "D": "Hope" }
mat_0154
multiple_choice
en
Choose: what measures spread?
[ "Squared deviations averaged.", "So: Variance.", "Select option A." ]
math
Answer: Variance Steps: 1. Squared deviations averaged. 2. So: Variance. 3. Select option A. Answer: (A)
probability
gcd = 6.
null
mat_0155
worked_example
en
Compute gcd(12, 18) step by step.
[ "Factor: 12=4×3, 18=6×3.", "Common: 3×gcd(4,6).", "= 3×2 = 6." ]
math
Answer: gcd = 6. Steps: 1. Factor: 12=4×3, 18=6×3. 2. Common: 3×gcd(4,6). 3. = 3×2 = 6.
number_theory
P(4,2) is 12.
{ "A": "8", "B": "16", "C": "12", "D": "20" }
mat_0156
multiple_choice
en
Compute P(4,2).
[ "4×3.", "= 12.", "Select option C." ]
math
Answer: 12 Steps: 1. 4×3. 2. = 12. 3. Select option C. Answer: (C)
combinatorics
Spor předpokládá nepravdivost a odvodí nesmysl, tvrzení tedy platí.
null
mat_0157
concept
cs
Proč důkaz sporem?
[ "Spor předpokládá nepravdivost a odvodí nesmysl, tvrzení tedy platí.", "Odpověď tedy platí: Spor předpokládá nepravdivost a odvodí nesmysl, tvrzení tedy platí." ]
math
Answer: Spor předpokládá nepravdivost a odvodí nesmysl, tvrzení tedy platí. Steps: 1. Spor předpokládá nepravdivost a odvodí nesmysl, tvrzení tedy platí. 2. Odpověď tedy platí: Spor předpokládá nepravdivost a odvodí nesmysl, tvrzení tedy platí.
proofs
f'(2) = 12.
null
mat_0158
worked_example
en
For f(x) = 2x² + 4x, compute f'(2) step by step.
[ "f'(x) = 4x + 4.", "Plug x = 2.", "4×2 + 4 = 12." ]
math
Answer: f'(2) = 12. Steps: 1. f'(x) = 4x + 4. 2. Plug x = 2. 3. 4×2 + 4 = 12.
calculus
Diagonal form powers matrices easily, since powers act separately on each eigen-direction.
null
mat_0159
concept
en
Why diagonalize?
[ "Diagonal form powers matrices easily, since powers act separately on each eigen-direction.", "So the answer stands: Diagonal form powers matrices easily, since powers act separately on each eigen-direction." ]
math
Answer: Diagonal form powers matrices easily, since powers act separately on each eigen-direction. Steps: 1. Diagonal form powers matrices easily, since powers act separately on each eigen-direction. 2. So the answer stands: Diagonal form powers matrices easily, since powers act separately on each eigen-direction.
linear_algebra
Prostor vypisuje všechny výsledky, pravděpodobnosti se vážou na úplnou množinu.
null
mat_0160
concept
cs
Proč prostor výsledků?
[ "Prostor vypisuje všechny výsledky, pravděpodobnosti se vážou na úplnou množinu.", "Odpověď tedy platí: Prostor vypisuje všechny výsledky, pravděpodobnosti se vážou na úplnou množinu." ]
math
Answer: Prostor vypisuje všechny výsledky, pravděpodobnosti se vážou na úplnou množinu. Steps: 1. Prostor vypisuje všechny výsledky, pravděpodobnosti se vážou na úplnou množinu. 2. Odpověď tedy platí: Prostor vypisuje všechny výsledky, pravděpodobnosti se vážou na úplnou množinu.
probability
Remainder: 5.
null
mat_0161
worked_example
en
Compute (61) mod 7.
[ "Divide 61 by 7.", "7×8 = 56.", "61 − 56 = 5." ]
math
Answer: Remainder: 5. Steps: 1. Divide 61 by 7. 2. 7×8 = 56. 3. 61 − 56 = 5.
number_theory
It fixes double-counting by alternating union sums, exact for overlapping sets.
null
mat_0162
concept
en
What is inclusion-exclusion?
[ "It fixes double-counting by alternating union sums, exact for overlapping sets.", "So the answer stands: It fixes double-counting by alternating union sums, exact for overlapping sets." ]
math
Answer: It fixes double-counting by alternating union sums, exact for overlapping sets. Steps: 1. It fixes double-counting by alternating union sums, exact for overlapping sets. 2. So the answer stands: It fixes double-counting by alternating union sums, exact for overlapping sets.
combinatorics
Polovina: 3, číslo 6 je sudé.
null
mat_0163
worked_example
cs
Ukaž, že N² + N je sudé pro N = 2, výpočtem poloviny.
[ "2² + 2 = 6.", "6 / 2 = 3.", "Celé číslo, tedy sudé." ]
math
Answer: Polovina: 3, číslo 6 je sudé. Steps: 1. 2² + 2 = 6. 2. 6 / 2 = 3. 3. Celé číslo, tedy sudé.
proofs
Integral: 216.
null
mat_0164
worked_example
en
Evaluate the integral of 3x² from 0 to 6.
[ "Antiderivative: x³.", "Evaluate 0 to 6.", "6³ − 0 = 216." ]
math
Answer: Integral: 216. Steps: 1. Antiderivative: x³. 2. Evaluate 0 to 6. 3. 6³ − 0 = 216.
calculus
Trace: 13.
null
mat_0165
worked_example
en
Compute the trace of [[6,0],[0,7]].
[ "Sum diagonal.", "6 + 7.", "= 13." ]
math
Answer: Trace: 13. Steps: 1. Sum diagonal. 2. 6 + 7. 3. = 13.
linear_algebra
Distributions list value probabilities compactly, summarizing all chance behaviour at once.
null
mat_0166
concept
en
Why distributions?
[ "Distributions list value probabilities compactly, summarizing all chance behaviour at once.", "So the answer stands: Distributions list value probabilities compactly, summarizing all chance behaviour at once." ]
math
Answer: Distributions list value probabilities compactly, summarizing all chance behaviour at once. Steps: 1. Distributions list value probabilities compactly, summarizing all chance behaviour at once. 2. So the answer stands: Distributions list value probabilities compactly, summarizing all chance behaviour at once.
probability
lcm = 24.
null
mat_0167
worked_example
en
Compute lcm(6, 8) step by step.
[ "gcd(6,8) = 2.", "6×8/2.", "= 24." ]
math
Answer: lcm = 24. Steps: 1. gcd(6,8) = 2. 2. 6×8/2. 3. = 24.
number_theory
P(3,2) je 6.
{ "A": "3", "B": "6", "C": "9", "D": "12" }
mat_0168
multiple_choice
cs
Vypočítej permutační číslo P(3,2).
[ "3×2.", "= 6.", "Vyber možnost B." ]
math
Answer: 6 Steps: 1. 3×2. 2. = 6. 3. Vyber možnost B. Answer: (B)
combinatorics
For-all and exists claims need different proofs, so naming the quantifier picks the right proof strategy.
null
mat_0169
concept
en
Why state quantifiers clearly?
[ "For-all and exists claims need different proofs, so naming the quantifier picks the right proof strategy.", "So the answer stands: For-all and exists claims need different proofs, so naming the quantifier picks the right proof strategy." ]
math
Answer: For-all and exists claims need different proofs, so naming the quantifier picks the right proof strategy. Steps: 1. For-all and exists claims need different proofs, so naming the quantifier picks the right proof strategy. 2. So the answer stands: For-all and exists claims need different proofs, so naming the qu...
proofs
Derivování nachází maxima, minima a rychlosti.
null
mat_0170
concept
cs
Proč derivovat?
[ "Derivování nachází maxima, minima a rychlosti.", "Odpověď tedy platí: Derivování nachází maxima, minima a rychlosti." ]
math
Answer: Derivování nachází maxima, minima a rychlosti. Steps: 1. Derivování nachází maxima, minima a rychlosti. 2. Odpověď tedy platí: Derivování nachází maxima, minima a rychlosti.
calculus
A vector space closes under addition and scaling, with axioms guaranteeing familiar algebra.
null
mat_0171
concept
en
What is a vector space?
[ "A vector space closes under addition and scaling, with axioms guaranteeing familiar algebra.", "So the answer stands: A vector space closes under addition and scaling, with axioms guaranteeing familiar algebra." ]
math
Answer: A vector space closes under addition and scaling, with axioms guaranteeing familiar algebra. Steps: 1. A vector space closes under addition and scaling, with axioms guaranteeing familiar algebra. 2. So the answer stands: A vector space closes under addition and scaling, with axioms guaranteeing familiar algebra...
linear_algebra
The probability is 1/7.
{ "A": "1/6", "B": "1/7", "C": "1/8", "D": "2/7" }
mat_0172
multiple_choice
en
A fair 7-sided die is rolled. What is the probability of one specific number?
[ "1 face of 7.", "P = 1/7.", "Select option B." ]
math
Answer: 1/7 Steps: 1. 1 face of 7. 2. P = 1/7. 3. Select option B. Answer: (B)
probability
It computes with remainders upon division, wrapping numbers around a modulus clock.
null
mat_0173
concept
en
What is modular arithmetic?
[ "It computes with remainders upon division, wrapping numbers around a modulus clock.", "So the answer stands: It computes with remainders upon division, wrapping numbers around a modulus clock." ]
math
Answer: It computes with remainders upon division, wrapping numbers around a modulus clock. Steps: 1. It computes with remainders upon division, wrapping numbers around a modulus clock. 2. So the answer stands: It computes with remainders upon division, wrapping numbers around a modulus clock.
number_theory
More items than boxes forces sharing, proving existence without construction.
null
mat_0174
concept
en
Why pigeonhole?
[ "More items than boxes forces sharing, proving existence without construction.", "So the answer stands: More items than boxes forces sharing, proving existence without construction." ]
math
Answer: More items than boxes forces sharing, proving existence without construction. Steps: 1. More items than boxes forces sharing, proving existence without construction. 2. So the answer stands: More items than boxes forces sharing, proving existence without construction.
combinatorics
A constructive proof exhibits the claimed object explicitly, giving both truth and a concrete example.
null
mat_0175
concept
en
What is a constructive proof?
[ "A constructive proof exhibits the claimed object explicitly, giving both truth and a concrete example.", "So the answer stands: A constructive proof exhibits the claimed object explicitly, giving both truth and a concrete example." ]
math
Answer: A constructive proof exhibits the claimed object explicitly, giving both truth and a concrete example. Steps: 1. A constructive proof exhibits the claimed object explicitly, giving both truth and a concrete example. 2. So the answer stands: A constructive proof exhibits the claimed object explicitly, giving bot...
proofs
Limit: 12.
null
mat_0176
worked_example
en
Evaluate the limit of (x² − 6²)/(x − 6) as x → 6.
[ "Factor: (x−6)(x+6).", "Cancel (x−6).", "Plug 6: 6+6 = 12." ]
math
Answer: Limit: 12. Steps: 1. Factor: (x−6)(x+6). 2. Cancel (x−6). 3. Plug 6: 6+6 = 12.
calculus
The answer is Dot product.
{ "A": "Dot product", "B": "Cross guess", "C": "Wild sum", "D": "Blind hope" }
mat_0177
multiple_choice
en
Choose: what measures angles?
[ "Zero means orthogonal.", "So: Dot product.", "Select option A." ]
math
Answer: Dot product Steps: 1. Zero means orthogonal. 2. So: Dot product. 3. Select option A. Answer: (A)
linear_algebra
It counts successes in fixed trials with constant p, modelling repeated yes-no experiments.
null
mat_0178
concept
en
What is the binomial distribution?
[ "It counts successes in fixed trials with constant p, modelling repeated yes-no experiments.", "So the answer stands: It counts successes in fixed trials with constant p, modelling repeated yes-no experiments." ]
math
Answer: It counts successes in fixed trials with constant p, modelling repeated yes-no experiments. Steps: 1. It counts successes in fixed trials with constant p, modelling repeated yes-no experiments. 2. So the answer stands: It counts successes in fixed trials with constant p, modelling repeated yes-no experiments.
probability
Congruences preserve sums and products, letting big-number questions shrink to small cases.
null
mat_0179
concept
en
Why congruences?
[ "Congruences preserve sums and products, letting big-number questions shrink to small cases.", "So the answer stands: Congruences preserve sums and products, letting big-number questions shrink to small cases." ]
math
Answer: Congruences preserve sums and products, letting big-number questions shrink to small cases. Steps: 1. Congruences preserve sums and products, letting big-number questions shrink to small cases. 2. So the answer stands: Congruences preserve sums and products, letting big-number questions shrink to small cases.
number_theory
C(9,3) = 84.
null
mat_0180
worked_example
en
Show the computation of C(9,3).
[ "n(n−1)(n−2)/6.", "9×8×7/6.", "= 84." ]
math
Answer: C(9,3) = 84. Steps: 1. n(n−1)(n−2)/6. 2. 9×8×7/6. 3. = 84.
combinatorics
Proving not-Q implies not-P is equivalent to P implies Q, and the flipped form is often easier.
null
mat_0181
concept
en
Why use contrapositive?
[ "Proving not-Q implies not-P is equivalent to P implies Q, and the flipped form is often easier.", "So the answer stands: Proving not-Q implies not-P is equivalent to P implies Q, and the flipped form is often easier." ]
math
Answer: Proving not-Q implies not-P is equivalent to P implies Q, and the flipped form is often easier. Steps: 1. Proving not-Q implies not-P is equivalent to P implies Q, and the flipped form is often easier. 2. So the answer stands: Proving not-Q implies not-P is equivalent to P implies Q, and the flipped form is oft...
proofs
A definite integral sums infinite thin slices, measuring area under a curve exactly.
null
mat_0182
concept
en
What is an integral?
[ "A definite integral sums infinite thin slices, measuring area under a curve exactly.", "So the answer stands: A definite integral sums infinite thin slices, measuring area under a curve exactly." ]
math
Answer: A definite integral sums infinite thin slices, measuring area under a curve exactly. Steps: 1. A definite integral sums infinite thin slices, measuring area under a curve exactly. 2. So the answer stands: A definite integral sums infinite thin slices, measuring area under a curve exactly.
calculus
The determinant is 4.
{ "A": "1", "B": "4", "C": "7", "D": "10" }
mat_0183
multiple_choice
en
Find the determinant of [[2,2],[3,5]].
[ "2×5 − 2×3.", "Det = 4.", "Select option B." ]
math
Answer: 4 Steps: 1. 2×5 − 2×3. 2. Det = 4. 3. Select option B. Answer: (B)
linear_algebra
Averages of many variables turn normal, so it models errors and natural variation.
null
mat_0184
concept
en
Why the normal distribution?
[ "Averages of many variables turn normal, so it models errors and natural variation.", "So the answer stands: Averages of many variables turn normal, so it models errors and natural variation." ]
math
Answer: Averages of many variables turn normal, so it models errors and natural variation. Steps: 1. Averages of many variables turn normal, so it models errors and natural variation. 2. So the answer stands: Averages of many variables turn normal, so it models errors and natural variation.
probability
The answer is Euclid's argument.
{ "A": "Euclid's argument", "B": "Big computers", "C": "Long lists", "D": "Loud claims" }
mat_0185
multiple_choice
en
Choose: what forces new primes?
[ "Product plus one.", "So: Euclid's argument.", "Select option A." ]
math
Answer: Euclid's argument Steps: 1. Product plus one. 2. So: Euclid's argument. 3. Select option A. Answer: (A)
number_theory
Kombinatorika počítá uspořádání a výběry.
null
mat_0186
concept
cs
Co je kombinatorika?
[ "Kombinatorika počítá uspořádání a výběry.", "Odpověď tedy platí: Kombinatorika počítá uspořádání a výběry." ]
math
Answer: Kombinatorika počítá uspořádání a výběry. Steps: 1. Kombinatorika počítá uspořádání a výběry. 2. Odpověď tedy platí: Kombinatorika počítá uspořádání a výběry.
combinatorics
The answer is One counterexample.
{ "A": "One counterexample", "B": "Two examples", "C": "Loud denial", "D": "Long proof" }
mat_0187
multiple_choice
en
Choose: what disproves a for-all claim?
[ "Single failure kills it.", "So: One counterexample.", "Select option A." ]
math
Answer: One counterexample Steps: 1. Single failure kills it. 2. So: One counterexample. 3. Select option A. Answer: (A)
proofs
f'(3) = 23.
null
mat_0188
worked_example
en
For f(x) = 3x² + 5x, compute f'(3) step by step.
[ "f'(x) = 6x + 5.", "Plug x = 3.", "6×3 + 5 = 23." ]
math
Answer: f'(3) = 23. Steps: 1. f'(x) = 6x + 5. 2. Plug x = 3. 3. 6×3 + 5 = 23.
calculus
The trace is 9.
{ "A": "7", "B": "11", "C": "9", "D": "13" }
mat_0189
multiple_choice
en
Find the trace of [[3,1],[2,6]].
[ "3 + 6.", "Trace = 9.", "Select option C." ]
math
Answer: 9 Steps: 1. 3 + 6. 2. Trace = 9. 3. Select option C. Answer: (C)
linear_algebra
Střední hodnota je 2,5.
{ "A": "3,5", "B": "2,5", "C": "1,5", "D": "4,5" }
mat_0190
multiple_choice
cs
Najdi střední hodnotu rovnoměrného tahu z {1..4}.
[ "(4+1)/2.", "E = 2,5.", "Vyber možnost B." ]
math
Answer: 2,5 Steps: 1. (4+1)/2. 2. E = 2,5. 3. Vyber možnost B. Answer: (B)
probability
The answer is Diophantine equation.
{ "A": "Real guess", "B": "Diophantine equation", "C": "Complex hope", "D": "Vague wish" }
mat_0191
multiple_choice
en
Choose: what seeks integer solutions?
[ "Gcd conditions apply.", "So: Diophantine equation.", "Select option B." ]
math
Answer: Diophantine equation Steps: 1. Gcd conditions apply. 2. So: Diophantine equation. 3. Select option B. Answer: (B)
number_theory
C(9,2) = 36.
null
mat_0192
worked_example
en
Show the computation of C(9,2).
[ "Formula n(n−1)/2.", "9×8/2.", "= 36." ]
math
Answer: C(9,2) = 36. Steps: 1. Formula n(n−1)/2. 2. 9×8/2. 3. = 36.
combinatorics
A lemma is a small proven helper claim, and breaking proofs into lemmas keeps each step checkable.
null
mat_0193
concept
en
What is a lemma?
[ "A lemma is a small proven helper claim, and breaking proofs into lemmas keeps each step checkable.", "So the answer stands: A lemma is a small proven helper claim, and breaking proofs into lemmas keeps each step checkable." ]
math
Answer: A lemma is a small proven helper claim, and breaking proofs into lemmas keeps each step checkable. Steps: 1. A lemma is a small proven helper claim, and breaking proofs into lemmas keeps each step checkable. 2. So the answer stands: A lemma is a small proven helper claim, and breaking proofs into lemmas keeps e...
proofs
Řetízkové pravidlo derivuje složeniny násobením vnější a vnitřní derivace.
null
mat_0194
concept
cs
Co je řetízkové pravidlo?
[ "Řetízkové pravidlo derivuje složeniny násobením vnější a vnitřní derivace.", "Odpověď tedy platí: Řetízkové pravidlo derivuje složeniny násobením vnější a vnitřní derivace." ]
math
Answer: Řetízkové pravidlo derivuje složeniny násobením vnější a vnitřní derivace. Steps: 1. Řetízkové pravidlo derivuje složeniny násobením vnější a vnitřní derivace. 2. Odpověď tedy platí: Řetízkové pravidlo derivuje složeniny násobením vnější a vnitřní derivace.
calculus
Independence means no vector is redundant, so each adds a new dimension to the span.
null
mat_0195
concept
en
Why check linear independence?
[ "Independence means no vector is redundant, so each adds a new dimension to the span.", "So the answer stands: Independence means no vector is redundant, so each adds a new dimension to the span." ]
math
Answer: Independence means no vector is redundant, so each adds a new dimension to the span. Steps: 1. Independence means no vector is redundant, so each adds a new dimension to the span. 2. So the answer stands: Independence means no vector is redundant, so each adds a new dimension to the span.
linear_algebra
Aktualizuje šanci při nové evidenci přes P(A|B).
null
mat_0196
concept
cs
Co je podmíněná pravděpodobnost?
[ "Aktualizuje šanci při nové evidenci přes P(A|B).", "Odpověď tedy platí: Aktualizuje šanci při nové evidenci přes P(A|B)." ]
math
Answer: Aktualizuje šanci při nové evidenci přes P(A|B). Steps: 1. Aktualizuje šanci při nové evidenci přes P(A|B). 2. Odpověď tedy platí: Aktualizuje šanci při nové evidenci přes P(A|B).
probability
gcd = 8.
null
mat_0197
worked_example
en
Compute gcd(16, 24) step by step.
[ "Factor: 16=4×4, 24=6×4.", "Common: 4×gcd(4,6).", "= 4×2 = 8." ]
math
Answer: gcd = 8. Steps: 1. Factor: 16=4×4, 24=6×4. 2. Common: 4×gcd(4,6). 3. = 4×2 = 8.
number_theory
P(4,3) = 24.
null
mat_0198
worked_example
cs
Ukaž výpočet P(4,3).
[ "n(n−1)(n−2).", "4×3×2.", "= 24." ]
math
Answer: P(4,3) = 24. Steps: 1. n(n−1)(n−2). 2. 4×3×2. 3. = 24.
combinatorics
Řádků: 8.
null
mat_0199
worked_example
cs
Důkaz prochází všechny případy 3 booleovských proměnných. Kolik řádků?
[ "2 volby každá.", "2^3 = 8." ]
math
Answer: Řádků: 8. Steps: 1. 2 volby každá. 2. 2^3 = 8.
proofs
Integral: 343.
null
mat_0200
worked_example
en
Evaluate the integral of 3x² from 0 to 7.
[ "Antiderivative: x³.", "Evaluate 0 to 7.", "7³ − 0 = 343." ]
math
Answer: Integral: 343. Steps: 1. Antiderivative: x³. 2. Evaluate 0 to 7. 3. 7³ − 0 = 343.
calculus
Matice kódují lineární zobrazení a soustavy kompaktně.
null
mat_0201
concept
cs
Proč matice?
[ "Matice kódují lineární zobrazení a soustavy kompaktně.", "Odpověď tedy platí: Matice kódují lineární zobrazení a soustavy kompaktně." ]
math
Answer: Matice kódují lineární zobrazení a soustavy kompaktně. Steps: 1. Matice kódují lineární zobrazení a soustavy kompaktně. 2. Odpověď tedy platí: Matice kódují lineární zobrazení a soustavy kompaktně.
linear_algebra
E = 4.5.
null
mat_0202
worked_example
en
Compute E of a uniform draw from {1..8}.
[ "Mean of 1..8.", "(8+1)/2.", "E = 4.5." ]
math
Answer: E = 4.5. Steps: 1. Mean of 1..8. 2. (8+1)/2. 3. E = 4.5.
probability
Remainder: 2.
null
mat_0203
worked_example
en
Compute (72) mod 7.
[ "Divide 72 by 7.", "7×10 = 70.", "72 − 70 = 2." ]
math
Answer: Remainder: 2. Steps: 1. Divide 72 by 7. 2. 7×10 = 70. 3. 72 − 70 = 2.
number_theory
Faktoriály počítají pořadí různých objektů.
null
mat_0204
concept
cs
Proč faktoriály?
[ "Faktoriály počítají pořadí různých objektů.", "Odpověď tedy platí: Faktoriály počítají pořadí různých objektů." ]
math
Answer: Faktoriály počítají pořadí různých objektů. Steps: 1. Faktoriály počítají pořadí různých objektů. 2. Odpověď tedy platí: Faktoriály počítají pořadí různých objektů.
combinatorics
Indukce dokáže základ a krok, tvrzení pak platí pro všechna přirozená čísla.
null
mat_0205
concept
cs
Co je indukce?
[ "Indukce dokáže základ a krok, tvrzení pak platí pro všechna přirozená čísla.", "Odpověď tedy platí: Indukce dokáže základ a krok, tvrzení pak platí pro všechna přirozená čísla." ]
math
Answer: Indukce dokáže základ a krok, tvrzení pak platí pro všechna přirozená čísla. Steps: 1. Indukce dokáže základ a krok, tvrzení pak platí pro všechna přirozená čísla. 2. Odpověď tedy platí: Indukce dokáže základ a krok, tvrzení pak platí pro všechna přirozená čísla.
proofs
Limit: 14.
null
mat_0206
worked_example
en
Evaluate the limit of (x² − 7²)/(x − 7) as x → 7.
[ "Factor: (x−7)(x+7).", "Cancel (x−7).", "Plug 7: 7+7 = 14." ]
math
Answer: Limit: 14. Steps: 1. Factor: (x−7)(x+7). 2. Cancel (x−7). 3. Plug 7: 7+7 = 14.
calculus
The dot product is 18.
{ "A": "14", "B": "22", "C": "26", "D": "18" }
mat_0207
multiple_choice
en
Find the dot product (2,3) · (3,4).
[ "2×3 + 3×4.", "Product = 18.", "Select option D." ]
math
Answer: 18 Steps: 1. 2×3 + 3×4. 2. Product = 18. 3. Select option D. Answer: (D)
linear_algebra
P(red) = 6/10.
null
mat_0208
worked_example
en
A bag holds 6 red and 4 blue marbles. Show P(red).
[ "Red: 6.", "Total: 10.", "P = 6/10." ]
math
Answer: P(red) = 6/10. Steps: 1. Red: 6. 2. Total: 10. 3. P = 6/10.
probability
The gcd is 12.
{ "A": "9", "B": "15", "C": "12", "D": "18" }
mat_0209
multiple_choice
en
Find gcd(24, 36).
[ "Factor 3 out twice.", "gcd = 12.", "Select option C." ]
math
Answer: 12 Steps: 1. Factor 3 out twice. 2. gcd = 12. 3. Select option C. Answer: (C)
number_theory
C(5,3) je 10.
{ "A": "5", "B": "15", "C": "10", "D": "20" }
mat_0210
multiple_choice
cs
Vypočítej kombinační číslo C(5,3).
[ "5×4×3/6.", "= 10.", "Vyber možnost C." ]
math
Answer: 10 Steps: 1. 5×4×3/6. 2. = 10. 3. Vyber možnost C. Answer: (C)
combinatorics
Half: 15, so 30 is even.
null
mat_0211
worked_example
en
Show N² + N is even for N = 5 by computing its half.
[ "5² + 5 = 30.", "30 / 2 = 15.", "Integer, so even." ]
math
Answer: Half: 15, so 30 is even. Steps: 1. 5² + 5 = 30. 2. 30 / 2 = 15. 3. Integer, so even.
proofs
f'(4) = 38.
null
mat_0212
worked_example
en
For f(x) = 4x² + 6x, compute f'(4) step by step.
[ "f'(x) = 8x + 6.", "Plug x = 4.", "8×4 + 6 = 38." ]
math
Answer: f'(4) = 38. Steps: 1. f'(x) = 8x + 6. 2. Plug x = 4. 3. 8×4 + 6 = 38.
calculus
Dot product: 35.
null
mat_0213
worked_example
en
Compute (5,4) · (3,5) step by step.
[ "Multiply components.", "5×3 + 4×5.", "= 35." ]
math
Answer: Dot product: 35. Steps: 1. Multiply components. 2. 5×3 + 4×5. 3. = 35.
linear_algebra
The expected value is 3.
{ "A": "4", "B": "2", "C": "3", "D": "5" }
mat_0214
multiple_choice
en
Find the expected value of a uniform draw from {1..5}.
[ "(5+1)/2.", "E = 3.", "Select option C." ]
math
Answer: 3 Steps: 1. (5+1)/2. 2. E = 3. 3. Select option C. Answer: (C)
probability
lcm = 56.
null
mat_0215
worked_example
en
Compute lcm(7, 8) step by step.
[ "gcd(7,8) = 1.", "7×8/1.", "= 56." ]
math
Answer: lcm = 56. Steps: 1. gcd(7,8) = 1. 2. 7×8/1. 3. = 56.
number_theory
C(6,3) = 20.
null
mat_0216
worked_example
cs
Ukaž výpočet C(6,3).
[ "n(n−1)(n−2)/6.", "6×5×4/6.", "= 20." ]
math
Answer: C(6,3) = 20. Steps: 1. n(n−1)(n−2)/6. 2. 6×5×4/6. 3. = 20.
combinatorics
Proofs rest on definitions, so stating exact meanings first prevents hidden assumptions and ambiguity.
null
mat_0217
concept
en
Why define terms first?
[ "Proofs rest on definitions, so stating exact meanings first prevents hidden assumptions and ambiguity.", "So the answer stands: Proofs rest on definitions, so stating exact meanings first prevents hidden assumptions and ambiguity." ]
math
Answer: Proofs rest on definitions, so stating exact meanings first prevents hidden assumptions and ambiguity. Steps: 1. Proofs rest on definitions, so stating exact meanings first prevents hidden assumptions and ambiguity. 2. So the answer stands: Proofs rest on definitions, so stating exact meanings first prevents hi...
proofs
Určitý integrál sčítá nekonečně tenké plátky a měří plochu pod křivkou.
null
mat_0218
concept
cs
Co je integrál?
[ "Určitý integrál sčítá nekonečně tenké plátky a měří plochu pod křivkou.", "Odpověď tedy platí: Určitý integrál sčítá nekonečně tenké plátky a měří plochu pod křivkou." ]
math
Answer: Určitý integrál sčítá nekonečně tenké plátky a měří plochu pod křivkou. Steps: 1. Určitý integrál sčítá nekonečně tenké plátky a měří plochu pod křivkou. 2. Odpověď tedy platí: Určitý integrál sčítá nekonečně tenké plátky a měří plochu pod křivkou.
calculus
The answer is Rank.
{ "A": "Rank", "B": "Size", "C": "Color", "D": "Age" }
mat_0219
multiple_choice
en
Choose: what counts image dimension?
[ "Independent rows tallied.", "So: Rank.", "Select option A." ]
math
Answer: Rank Steps: 1. Independent rows tallied. 2. So: Rank. 3. Select option A. Answer: (A)
linear_algebra
P(red) is 3/10.
{ "A": "7/10", "B": "3/11", "C": "4/10", "D": "3/10" }
mat_0220
multiple_choice
en
A bag holds 3 red and 7 blue marbles. What is P(red)?
[ "3 of 10.", "P = 3/10.", "Select option D." ]
math
Answer: 3/10 Steps: 1. 3 of 10. 2. P = 3/10. 3. Select option D. Answer: (D)
probability
NSD = 6.
null
mat_0221
worked_example
cs
Spočítej NSD(12, 18) krok za krokem.
[ "Rozlož: 12=4×3, 18=6×3.", "Společné: 3×NSD(4,6).", "= 3×2 = 6." ]
math
Answer: NSD = 6. Steps: 1. Rozlož: 12=4×3, 18=6×3. 2. Společné: 3×NSD(4,6). 3. = 3×2 = 6.
number_theory
P(8,3) = 336.
null
mat_0222
worked_example
en
Show the computation of P(8,3).
[ "n(n−1)(n−2).", "8×7×6.", "= 336." ]
math
Answer: P(8,3) = 336. Steps: 1. n(n−1)(n−2). 2. 8×7×6. 3. = 336.
combinatorics
Rows: 64.
null
mat_0223
worked_example
en
A proof checks all cases of 6 boolean variables. How many rows?
[ "2 choices each.", "2^6 = 64." ]
math
Answer: Rows: 64. Steps: 1. 2 choices each. 2. 2^6 = 64.
proofs
The derivative is 11.
{ "A": "9", "B": "11", "C": "13", "D": "15" }
mat_0224
multiple_choice
en
For f(x) = 2x² + 3x, find f'(2).
[ "f'(x) = 4x + 3.", "At 2: 11.", "Select option B." ]
math
Answer: 11 Steps: 1. f'(x) = 4x + 3. 2. At 2: 11. 3. Select option B. Answer: (B)
calculus
Skalární součin: 11.
null
mat_0225
worked_example
cs
Spočítej (2,1) · (3,5) krok za krokem.
[ "Násob složky.", "2×3 + 1×5.", "= 11." ]
math
Answer: Skalární součin: 11. Steps: 1. Násob složky. 2. 2×3 + 1×5. 3. = 11.
linear_algebra
The answer is Conditional probability.
{ "A": "Conditional probability", "B": "Blind guess", "C": "Stubborn prior", "D": "Wild hope" }
mat_0226
multiple_choice
en
Choose: what updates with evidence?
[ "Space shrinks, ratio taken.", "So: Conditional probability.", "Select option A." ]
math
Answer: Conditional probability Steps: 1. Space shrinks, ratio taken. 2. So: Conditional probability. 3. Select option A. Answer: (A)
probability
The remainder is 6.
{ "A": "7", "B": "8", "C": "0", "D": "6" }
mat_0227
multiple_choice
en
Find (114) mod 9.
[ "114 ÷ 9.", "Remainder 6.", "Select option D." ]
math
Answer: 6 Steps: 1. 114 ÷ 9. 2. Remainder 6. 3. Select option D. Answer: (D)
number_theory
C(6,3) is 20.
{ "A": "14", "B": "26", "C": "32", "D": "20" }
mat_0228
multiple_choice
en
Compute C(6,3).
[ "6×5×4/6.", "= 20.", "Select option D." ]
math
Answer: 20 Steps: 1. 6×5×4/6. 2. = 20. 3. Select option D. Answer: (D)
combinatorics
Protipříklad je případ, kde obecné tvrzení selže, a sám je vyvrátí.
null
mat_0229
concept
cs
Co je protipříklad?
[ "Protipříklad je případ, kde obecné tvrzení selže, a sám je vyvrátí.", "Odpověď tedy platí: Protipříklad je případ, kde obecné tvrzení selže, a sám je vyvrátí." ]
math
Answer: Protipříklad je případ, kde obecné tvrzení selže, a sám je vyvrátí. Steps: 1. Protipříklad je případ, kde obecné tvrzení selže, a sám je vyvrátí. 2. Odpověď tedy platí: Protipříklad je případ, kde obecné tvrzení selže, a sám je vyvrátí.
proofs
The integral is 27.
{ "A": "24", "B": "30", "C": "27", "D": "33" }
mat_0230
multiple_choice
en
Compute the integral of 3x² from 0 to 3.
[ "Antiderivative x³.", "3³ = 27.", "Select option C." ]
math
Answer: 27 Steps: 1. Antiderivative x³. 2. 3³ = 27. 3. Select option C. Answer: (C)
calculus
The answer is Projection.
{ "A": "Guessing", "B": "Projection", "C": "Hoping", "D": "Waiting" }
mat_0231
multiple_choice
en
Choose: what finds closest point?
[ "Error orthogonal.", "So: Projection.", "Select option B." ]
math
Answer: Projection Steps: 1. Error orthogonal. 2. So: Projection. 3. Select option B. Answer: (B)
linear_algebra
P = 1/10.
null
mat_0232
worked_example
en
A fair 10-sided die is rolled. Show P(one specific number).
[ "Favourable: 1.", "Possible: 10.", "P = 1/10." ]
math
Answer: P = 1/10. Steps: 1. Favourable: 1. 2. Possible: 10. 3. P = 1/10.
probability
Prvočísla jsou atomy násobení, každé číslo se jednoznačně rozkládá.
null
mat_0233
concept
cs
Proč prvočísla?
[ "Prvočísla jsou atomy násobení, každé číslo se jednoznačně rozkládá.", "Odpověď tedy platí: Prvočísla jsou atomy násobení, každé číslo se jednoznačně rozkládá." ]
math
Answer: Prvočísla jsou atomy násobení, každé číslo se jednoznačně rozkládá. Steps: 1. Prvočísla jsou atomy násobení, každé číslo se jednoznačně rozkládá. 2. Odpověď tedy platí: Prvočísla jsou atomy násobení, každé číslo se jednoznačně rozkládá.
number_theory
The answer is nCr.
{ "A": "nCr", "B": "n+r", "C": "n*r", "D": "n+r!" }
mat_0234
multiple_choice
en
Choose: what counts subsets?
[ "Order divided out.", "So: nCr.", "Select option A." ]
math
Answer: nCr Steps: 1. Order divided out. 2. So: nCr. 3. Select option A. Answer: (A)
combinatorics
The answer is Every possibility.
{ "A": "Easy ones", "B": "Every possibility", "C": "First two", "D": "Odd cases" }
mat_0235
multiple_choice
en
Choose: what must cases cover?
[ "Gaps break proofs.", "So: Every possibility.", "Select option B." ]
math
Answer: Every possibility Steps: 1. Gaps break proofs. 2. So: Every possibility. 3. Select option B. Answer: (B)
proofs
The limit is 6.
{ "A": "4", "B": "8", "C": "10", "D": "6" }
mat_0236
multiple_choice
en
Find the limit of (x² − 3²)/(x − 3) as x → 3.
[ "Factor (x−3)(x+3).", "Cancel, get 2×3 = 6.", "Select option D." ]
math
Answer: 6 Steps: 1. Factor (x−3)(x+3). 2. Cancel, get 2×3 = 6. 3. Select option D. Answer: (D)
calculus
A basis is an independent spanning set, giving every vector unique coordinates.
null
mat_0237
concept
en
What is a basis?
[ "A basis is an independent spanning set, giving every vector unique coordinates.", "So the answer stands: A basis is an independent spanning set, giving every vector unique coordinates." ]
math
Answer: A basis is an independent spanning set, giving every vector unique coordinates. Steps: 1. A basis is an independent spanning set, giving every vector unique coordinates. 2. So the answer stands: A basis is an independent spanning set, giving every vector unique coordinates.
linear_algebra
E = 5.
null
mat_0238
worked_example
en
Compute E of a uniform draw from {1..9}.
[ "Mean of 1..9.", "(9+1)/2.", "E = 5." ]
math
Answer: E = 5. Steps: 1. Mean of 1..9. 2. (9+1)/2. 3. E = 5.
probability
Zbytek: 5.
null
mat_0239
worked_example
cs
Spočítej (61) mod 7.
[ "Děl 61 sedmi.", "7×8 = 56.", "61 − 56 = 5." ]
math
Answer: Zbytek: 5. Steps: 1. Děl 61 sedmi. 2. 7×8 = 56. 3. 61 − 56 = 5.
number_theory
The answer is Bijection.
{ "A": "Wild map", "B": "Bijection", "C": "Blind guess", "D": "Vague hope" }
mat_0240
multiple_choice
en
Choose: what pairs sets equally?
[ "Inverse proves size.", "So: Bijection.", "Select option B." ]
math
Answer: Bijection Steps: 1. Inverse proves size. 2. So: Bijection. 3. Select option B. Answer: (B)
combinatorics
The table has 16 rows.
{ "A": "14", "B": "18", "C": "16", "D": "20" }
mat_0241
multiple_choice
en
How many rows does a truth table with 4 variables have?
[ "2^4 rows.", "Total: 16.", "Select option C." ]
math
Answer: 16 Steps: 1. 2^4 rows. 2. Total: 16. 3. Select option C. Answer: (C)
proofs
Integrál: 27.
null
mat_0242
worked_example
cs
Vyčísli integrál 3x² od 0 do 3.
[ "Primitivní: x³.", "Vyčísli 0 až 3.", "3³ − 0 = 27." ]
math
Answer: Integrál: 27. Steps: 1. Primitivní: x³. 2. Vyčísli 0 až 3. 3. 3³ − 0 = 27.
calculus
Dimension is the basis size, fixing how many numbers describe every vector exactly.
null
mat_0243
concept
en
Why count dimension?
[ "Dimension is the basis size, fixing how many numbers describe every vector exactly.", "So the answer stands: Dimension is the basis size, fixing how many numbers describe every vector exactly." ]
math
Answer: Dimension is the basis size, fixing how many numbers describe every vector exactly. Steps: 1. Dimension is the basis size, fixing how many numbers describe every vector exactly. 2. So the answer stands: Dimension is the basis size, fixing how many numbers describe every vector exactly.
linear_algebra
Sample averages converge to expectation as trials grow, justifying statistics from data.
null
mat_0244
concept
en
What is the law of large numbers?
[ "Sample averages converge to expectation as trials grow, justifying statistics from data.", "So the answer stands: Sample averages converge to expectation as trials grow, justifying statistics from data." ]
math
Answer: Sample averages converge to expectation as trials grow, justifying statistics from data. Steps: 1. Sample averages converge to expectation as trials grow, justifying statistics from data. 2. So the answer stands: Sample averages converge to expectation as trials grow, justifying statistics from data.
probability
gcd = 10.
null
mat_0245
worked_example
en
Compute gcd(20, 30) step by step.
[ "Factor: 20=4×5, 30=6×5.", "Common: 5×gcd(4,6).", "= 5×2 = 10." ]
math
Answer: gcd = 10. Steps: 1. Factor: 20=4×5, 30=6×5. 2. Common: 5×gcd(4,6). 3. = 5×2 = 10.
number_theory
A permutation orders objects, and n distinct objects admit exactly n! orders.
null
mat_0246
concept
en
What is a permutation?
[ "A permutation orders objects, and n distinct objects admit exactly n! orders.", "So the answer stands: A permutation orders objects, and n distinct objects admit exactly n! orders." ]
math
Answer: A permutation orders objects, and n distinct objects admit exactly n! orders. Steps: 1. A permutation orders objects, and n distinct objects admit exactly n! orders. 2. So the answer stands: A permutation orders objects, and n distinct objects admit exactly n! orders.
combinatorics
Sum: 55.
null
mat_0247
worked_example
en
Prove by formula: find the sum 1 + 2 + ... + 10.
[ "Pair 1+10, 2+9, ...", "Use 10×11/2.", "= 55." ]
math
Answer: Sum: 55. Steps: 1. Pair 1+10, 2+9, ... 2. Use 10×11/2. 3. = 55.
proofs
Integrace obnovuje úhrny z rychlostí, počítá plochy a objemy.
null
mat_0248
concept
cs
Proč integrovat?
[ "Integrace obnovuje úhrny z rychlostí, počítá plochy a objemy.", "Odpověď tedy platí: Integrace obnovuje úhrny z rychlostí, počítá plochy a objemy." ]
math
Answer: Integrace obnovuje úhrny z rychlostí, počítá plochy a objemy. Steps: 1. Integrace obnovuje úhrny z rychlostí, počítá plochy a objemy. 2. Odpověď tedy platí: Integrace obnovuje úhrny z rychlostí, počítá plochy a objemy.
calculus
Determinant: 40.
null
mat_0249
worked_example
en
Compute det [[6,1],[2,7]] step by step.
[ "ad − bc.", "6×7 − 1×2.", "= 40." ]
math
Answer: Determinant: 40. Steps: 1. ad − bc. 2. 6×7 − 1×2. 3. = 40.
linear_algebra
The answer is Normal distribution.
{ "A": "Wild guess", "B": "Normal distribution", "C": "Flat line", "D": "Single dot" }
mat_0250
multiple_choice
en
Choose: what models error bells?
[ "Averages turn normal.", "So: Normal distribution.", "Select option B." ]
math
Answer: Normal distribution Steps: 1. Averages turn normal. 2. So: Normal distribution. 3. Select option B. Answer: (B)
probability