## Fourier Series

Can't find coefficients for i=Asin(omega*t) for 0<t<T/2 and i=0 for T/2<t<T , i=f(t+T) I am getting for a0=0 but I think its not wright. Another one I can't find solution is f(x) = cos (x) 0<x<Pi/2 and f(x) = 0 for Pi/2 < x < Pi f(x) = F(x+2Pi) Would appriciate any help!