The question on my homework reads:

Determine the Fourier Series representation of the signal x(t) = cos(2t+pi/4). If the impulse response of the system is h(t) = e^(-t)*u(t), what is the output y(t)?

I can find the fourier series representation of x(t) no problem. My question is, do you have to use that answer to evaluate the convolution, or are the two pretty much separate questions, using same signal?