Fourier Series

I am trying to self teach myself Fourier series. I am stuck on how to solve a piecewise function Fourier series. f(x) = 1 when x is between 0 and pi, f(x) = 2 when x is between pi and 2pi. 

Thanks in advance. 

Sketch the piecewise function shown below. 

The piecewise function f(x) is given by 

f(x)=  2 when x>0

          -2 when x<0 

           0  when x=0 what is the value of f(2).

The piecewise function f(x) is given by 

f(x)=  2 when x>0

          -2 when x<0 

           0  when x=0 what is the value of f(2).