# Fourier Series coefficients, orthogonal?

## Homework Statement

Hello. I need help with orthogonality of the fourier series coefficients. I know you can use the dirac delta function, (or the kronecker function) in the orthogonality relationship. I want to try and see the derivation using complex form rather than sines and cosines.

## Homework Equations

proof of
$\frac{1}{T}\int^T_0 e^{inw_0t}e^{-imw_0t} dt = \delta_{m}{n}$

## The Attempt at a Solution

Basically I havent got very far, do not know where to start in this proof. any help would be appreciated?

thanks

Obviously, m and n must be integers, which makes things really easy. Just assume m=n, do the integration and write down what you get. Then assume $m \neq n$, do the integration and write down what you get.