Given f(x) = |sinx|

f(x) = |sinx| = sinx

f(-x) = |sin(-x)| = sinx

Hence f(x) = f(-x)

$\therefore$ |sinx| is even function

The Fourier series of an even function contains only cosine terms and is known as Fourier Series and is given by

$f(x) = \frac{a_{0}}{2} + \sum\limits_{n = …