- #1

richyw

- 180

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## Homework Statement

I am going over a practice exam, and I need to find the FSS of [tex]f(x)=x(\pi^2-x^2)[/tex]

## Homework Equations

[tex]f(x) \sim \sum^\infty_{n=1}a_n sin\left(\frac{n \pi x}{L}\right)[/tex]

[tex]a_n=\frac{2}{L}\int^L_0 f(x)sin\left(\frac{n\pi x}{L}\right)dx[/tex]

## The Attempt at a Solution

I think I need to integrate[tex]\frac{2}{\pi}\int^\pi_0 x(\pi^2-x^2)sin(n\pi)dx[/tex]which is two integrals, the first one would need me to use IBP once, and the second one would need me to use IBP three times. This is on a practice exam (and my exam is in an hour), so I am guessing that this integral is easier if I can find some symmetry in it. Is this true?