1. The problem statement, all variables and given/known data x(t) is input into a perfect lowpass filter with frequency response H(ω), having a bandwidth of BHz and a passband gain of 1. For B = (2πT)^-1 Hz, calculate the ratio of the output signal energy to the input signal energy. 2. Relevant equations x(t) = Ae^-|t|/T 3. The attempt at a solution I have found the input energy to be (A^2)/2 but I'm unable to find any equation which links the frequency response to the bandwidth in order to get the output energy. I have that |H(ω)| = gain. I've a feeling I'm missing something very basic here.