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Is A the inverse of B?
Given a matrix A and a matrix B, is A the inverse of B? >>A=[2,4;3,5]; >>B=[-2.5,2;1.5,-1]; >>isInverse...
1 month 前
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Rotate Matrix @180 degree
Rotate Matrix @180 degree Example A=[8 1 6; 3 5 7; 4 9 2], then answer would be [2 9 4;...
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Square root
Given x (a matrix), give back another matrix, where all the elements are the square roots of x's elements.
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the average value of the elements
Calculate the average value of the elements in the array
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Rule of mixtures (composites) - lower and upper bounds
The <http://en.wikipedia.org/wiki/Rule_of_mixtures rule of mixtures> is used in the mechanical design of composite structures to...
1 month 前
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Rule of mixtures (composites) - upper bound
The <http://en.wikipedia.org/wiki/Rule_of_mixtures rule of mixtures> is used in the mechanical design of composite structures to...
1 month 前
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Rule of mixtures (composites) - lower bound
The <http://en.wikipedia.org/wiki/Rule_of_mixtures rule of mixtures> is used in the mechanical design of composite structures to...
1 month 前
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Stress-Strain Properties - 6
The total energy absorbed by a material up to failure in a tensile test is termed the absorbed strain energy. With respect to th...
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Stress-Strain Properties - 5
Similar to the previous problem, materials may be characterized by their stiffness-to-weight ratio, which is the elastic modulus...
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Stress-Strain Properties - 4
A common measure of the ability of a material to carry load per unit mass is termed strength-to-weight ratio and is calculated b...
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Stress-Strain Properties - 3
A brittle material will not exhibit a yield point. In other words, the yield point and failure point coincide. In such cases, th...
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Stress-Strain Properties - 2
The resilience of a material is its ability to resist permanent (or plastic) deformation. The resilience coincides with the elas...
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Stress-Strain Properties - 1
This is the first in a series of problems regarding mechanics of materials, in particular, material properties drawn from stress...
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Linear primes p' = mp + n
Problem statement List the prime numbers of the form p' = mp + n for a given (m,n) couple and such that p' < k, k positive in...
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List the complementary / symetric prime couples
Problem statement For a given positive integer n, provide the prime couples (p,p') such that p + p' = 10^n. NB : a number li...
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Check Legendre's conjecture
Context and problem statement Legendre's conjecture states for a given positive integer n, there always exists at least one pri...
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List the twin prime couples
Problem statement The twin prime couples (p,p') are the ones such that p' = p + 2. For a given integer n > 1, list the twin p...
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Check Bertrand-Chebyshev's theorem about prime numbers
Historical context Bertrand's postulate, also later known as Chebyshev's theorem, is a very important theorem in number theory ...
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Check p = 6n +/- 1, the generic formula for odd prime numbers greater than 3
Problem statement For all odd prime number p greater than 3, there exists a positive integer n, such that p = 6n +/- 1 : ...
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Check p = 4n +/- 1, the generic formula for odd prime numbers
Problem statement For all odd prime number p, there exists a positive integer n, such that p = 4n +/- 1 : Check this f...
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Chek the Delta = p' - p = 6k gap theorem about arithmetic progressions in the prime number set
Context In the prime numbers set there are some arithmetic progressions (sequences of three or more consecutive prime number...
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List the near-square primes, p = n² + 1 (Landau's 4th problem)
Historical context At the 1912 International Congress of Mathematicians, Edmund Landau listed four basic problems about prime...
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