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[tex]\int_{-a}^{a} x^{2} cos\left( a x^{2} \right) dx[/tex]

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- Thread starter maze
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- #1

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[tex]\int_{-a}^{a} x^{2} cos\left( a x^{2} \right) dx[/tex]

- #2

Defennder

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- #3

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I was hoping that perhaps it had a nice representation due to the limits of integration.

edit: I also don't particularly trust maple, as there have been times in the past where it couldn't do integrals that I could. (or perhaps I am using it wrong)

edit: I also don't particularly trust maple, as there have been times in the past where it couldn't do integrals that I could. (or perhaps I am using it wrong)

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- #4

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From the looks of it, it's symmetric, so you can change the limits of integration from 0 to a and multiplying your integral by 2. Idk if that helps at all or not :pI was hoping that perhaps it had a nice representation due to the limits of integration.

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- #6

Defennder

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By the way, if you want your thread to be moved back you should request a PF mentor by private messaging to do so.

- #7

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>> f = x^2*cos(x^2);

>> int (f,x)

ans =

1/2*sin(x^2)*x-1/4*2^(1/2)*pi^(1/2)*FresnelS(2^(1/2)/pi^(1/2)*x)

>> int(f,x,-1,1)

ans =

sin(1)-1/2*2^(1/2)*pi^(1/2)*FresnelS(2^(1/2)/pi^(1/2))

Matlab did same ><

I wanted to prove that Matlab is better

"edit: I also don't particularly trust maple, as there have been times in the past where it couldn't do integrals that I could. (or perhaps I am using it wrong)"

sometimes, you need to put the function in integrable form ... (computer's dun think)

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