Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Signal Power

  1. Jan 19, 2009 #1
    1. The problem statement, all variables and given/known data

    Finding the total power in the signal y(t) = (sin t + j cos t)(u(t − 2) − u(t − 4)) .

    2. Relevant equations


    E= integral from -infinity to + infinity abs(x(t))^2 dt

    signal has finite energy if < infi


    3. The attempt at a solution

    (sin t + j cos t) = exp(jpiet)


    is this the right direction here?

    exp(jt)= 2cos(x)^2 -1 + 2sin(x)cos(x) * j

    i made the assumption that

    when you take integral of the (u(t − 2) − u(t − 4))

    its from 2-4 since the step function is = 1 and its delayed i dont know if this is correct


    integral from 2 to 4 of (2cos(x)^2-1)

    i thought i could leave out the imaginary parts
     
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted