X (t) is a wide sense stationary zero mean Gaussian process with auto-correlation function Rxx(7) and power spectrum Sxx (w). Consider the process Z (t) = X(t) cos(wot + 0) + X2(t - T) sin(wot + 0) and 0 ~ U(0, 27) independent of X (t). Find the power spectrum of Z (t) and express it in terms of Sxx (w) and wo