Linked Questions

4
votes
1answer
980 views

Use of $Assumptions [duplicate]

I don't really understand the behaviour and the usage of $Assumption. For instance, when I set $Assumptions = λ > 0, I expect ...
5
votes
1answer
184 views

Simplification of integrals depending on a parameter [duplicate]

Assuming[Element[n, Integers], Integrate[Sin[x]*Sin[n*x],{x,0,Pi}]] returns 0, which is obviously wrong for n=1. ...
6
votes
0answers
80 views

When and why are Assuming and Assumptions not equivalent? [duplicate]

In this question there's an example of an integral where using Assuming and Assumptions give different results: ...
0
votes
1answer
64 views

strange result with trigonometric triple integral [duplicate]

I'm defining functions e[k_, t_] := Cos[Pi (k - 1) t] cosIntRaw[k_, l_, m_] := Integrate[e[k, t] e[l, t] e[m, t], {t, 0, 1}] cosInt[k_, l_, m_] := Assuming[Element[{k, l, m}, ...
6
votes
1answer
305 views

How to code around known MMa special-case failures?

Fourier Analysis and Signal Processing often require these integrals on functions f[x] that won't be known in advance. ...
6
votes
1answer
972 views

Simplify $\cos(n \pi)$ and $\sin(n \pi)$ when n is an integer

I was trying to calculate this integral in Mathematica 9: 2/π Integrate[ Cosh[a x] Cos[n x], {x, 0, π}, Assumptions -> n ∈ Integers] I got as a result : ...
3
votes
3answers
243 views

How to deal with units in logarithms?

I'm trying to take a formula, take it's integral which yields a formula with logarithms, and then directly plug in values with units and get an answer. However if the units go into any of the ...
5
votes
3answers
221 views

Calculate integral for arbitrary parameter n in infinite square well problem

I'm continuing[1,2] the study of an infinite square well in the context of quantum mechanics. Ultimate goal is to calculate the product $\Delta x\Delta k$, for various eigenstates, that is for ...
4
votes
2answers
196 views

How to force correct answers for Integrals of Cos[mx]*Cos[nx]? [duplicate]

This is a big problem if you do anything with a Fourier Series. This statement: Assuming[Element[{m, n}, Integers], Integrate[Cos[m*x]*Cos[n*x], {x, 0, 2 Pi}]] ...
4
votes
1answer
182 views

Why does Assuming for Integrate not work as expected?

I'm trying to perform the following integral with Mathematica 7: ...
3
votes
0answers
144 views

Is this result wrong because of calculation time? (and more questions about Assumptions)

I am confused with the Integrate Given by Mathematica. First let's see a one-dimensional case: ...
0
votes
0answers
61 views

Inconsistent behavior of Assuming[] in combination with Simplify[]

The following integral gives the correct result ...