## Fourier series notes

Fourier series is an expansion of a periodic function of period $2\pi$ which is representation of a function in a series of sine or cosine such as $f(x)=a_{0}+\sum_{n=1}^{\infty }a_{n}cos(nx)+\sum_{n=1}^{\infty }b_{n}sin(nx)$ where $a_{0} $, $a_{n}$ and $b_{n}$ are constants and are known as Fourier coefficients. In applying Fourier theorem for analysis of a complex periodic function, given function must satisfy the following condition (i) It …