Convolutions, Fourier Series...

Discussion in 'Homework Help' started by eazhar, Mar 16, 2007.

  1. eazhar

    Thread Starter New Member

    Mar 16, 2007
    Hi guys I just discovered this board and this will be my first post

    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?
  2. DrNick

    Active Member

    Dec 13, 2006
    just compute the convolution intigral, OR you can take the laplace transform of both, multiply and do the inverse transform (because convolution in time => multiplication in frequency). These are two seperate questions.
  3. Dave

    Retired Moderator

    Nov 17, 2003
    Agreed. This is the approach I would recommend you take.