Fourier Series Homework (Discontinuous Function)

1. The problem statement, all variables and given/known data

I have attached a screenshot of the question.

I know how to use Fourier's theorem for one function but have no idea how to attempt it with a discontinuous function like this.

I tried working out a0 by integrating both functions...



Fourier Series Homework (Discontinuous Function)

Fourier Series Homework (Discontinuous Function)