Linked Questions

4 votes
1 answer
3k 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 ...
altroware's user avatar
  • 274
6 votes
1 answer
300 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. ...
chris's user avatar
  • 63
3 votes
3 answers
477 views

Integral of trigonometric function gives different answer [duplicate]

I am working on an integral on the following trigonometric functions $$\int_{-\pi}^\pi \frac{\cos[(4m+2)x] \cos[(4m+1)x]}{\cos x}dx$$ where $m$ is positive integer. I am running the following code ...
user1285419's user avatar
-1 votes
1 answer
138 views

Integration with Assumption, why doesn't it simplify? [duplicate]

I have a problem which surely someone else had on here, but in reading similar questions, I haven't found an answer. The problem is really trivial: ...
Enrico M.'s user avatar
  • 867
9 votes
0 answers
154 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: ...
Szabolcs's user avatar
  • 234k
2 votes
1 answer
128 views

Getting wrong result when Integrating under an assumption [duplicate]

The simple integral $$\int_0^b \cos\left(\frac{2\pi m(y-\eta)}{b}\right) \cos\left(\frac{2\pi \eta}{b}\right)\mathrm{d}\eta$$ can be easily evaluated by Mathematica as, ...
sebqas's user avatar
  • 605
4 votes
0 answers
150 views

Puzzled by Assumptions [duplicate]

I don't know if this has already been discussed. Integrate[BesselJ[2 m + 1, x], {x, 0, ∞}, Assumptions -> m ϵ Integers] ...
Dimitris's user avatar
  • 4,794
0 votes
1 answer
93 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}, ...
agw's user avatar
  • 1
2 votes
1 answer
45 views

mathematica not specifying indeterminate cases in integrals/simplifications [duplicate]

I think this is undesirable behavior in a new version. Integrate[Cos[l*θ]*Sin[lp*θ]*Sin[θ], {θ, 0, π}] Will return the formula: ...
john parkhill's user avatar
0 votes
0 answers
58 views

Why does Mathematica neglect this special case for a double integral? [duplicate]

I was running the following script in Mathematica ...
Wolpertinger's user avatar
0 votes
0 answers
42 views

Using assumptions with Integrate [duplicate]

I open Mathematica and execute this code: ...
Mariusz Iwaniuk's user avatar
14 votes
3 answers
2k views

Remove Abs from Norms of Vectors

I have the following norm Norm[{a, b*c}] (* Sqrt[Abs[a]^2 + Abs[b c]^2] *) How do I remove the Abs from it? ...
chr's user avatar
  • 175
14 votes
1 answer
642 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. ...
Jerry Guern's user avatar
  • 4,602
6 votes
3 answers
333 views

Integral $\int_{d_1}^{d_2} \int_{-L/2}^{L/2} \int_{-L/2}^{L/2} \frac{1}{(x^2+y^2+z^2)^3} dx dy dz$

I'm trying to calculate the following integral in Mathematica, but it seems it doesn't return an analytical closed form, neither when I give numeric values for both $d_{1,2}$ and $L$. $$∫_{d_1}^{...
sined's user avatar
  • 583
8 votes
1 answer
5k 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 : $$\...
Cydonia7's user avatar
  • 2,519

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