# Proof of Fourier Series Coeffecients

podjackel

## Homework Equations

Integral of a series can be assumed to be the sum of integrals

## The Attempt at a Solution

Picture of Work

I am not sure where to proceed from here, advice?

R136a1
Try to explicitely calculate

$$\int_0^\lambda A_n \cos(\frac{2\pi n}{\lambda}x)dx$$

brmath
Try to explicitely calculate

$$\int_0^\lambda A_n \cos(\frac{2\pi n}{\lambda}x)dx$$