# Fourier series - question

Homework Statement
f(x) = |sin x|, -pi < x < pi, f(x) = f(x + 2pi)

Determine the Fourier series of f(x)

The attempt at a solution
I am unsure how to evaluate an integral with absolute signs in it, however, I am wondering if I could reduce the bounds to 0<x<pi and and f(x) = sin x and assume an even function extension (cosine extension). When I sketch these I obtain the same graph.

Am I able to do this?

Last edited:

vela
Staff Emeritus