# Signal Power

1. Jan 19, 2009

### jeir35

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

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