Fourier Series for ex and Parseval Identity | Simple Problem Solution

[springo]

Homework Statement

Find the Fourier series for e^x for x in (-1,1).
Find the Parseval identity.

Homework Equations

The Attempt at a Solution

$$c_{n}=\frac{1}{2}\int_{-1}^{1}e^{x}e^{-i n x}dx$$
Where c_n are the coefficients of the Fourier series.

I tried plotting
$$\sum_{k=-\infty}^{\infty}c_{n}e^{i n x}$$
together with e^x and it doesn't seem to be correct...

Thank you for your help!

 

[LCKurtz]

For starters, your formula for c_n is wrong. For period P = 2p:

$$c_n = \frac 1 {2p}\int_{-p}^p f(x) e^{\frac {i n \pi}{p}}dx$$

In your problem p = 1.