Prove the following which is an extension of Parseval's Theorem to multiple signals 00 . CO X1 (t) X2(t ) dt = 2 It X1(w) X2(-w)dw -DO -00 where, w = 2nf, rad/sec HINT - consider the Fourier Transform of the product, x1 (t) X2(t) as a convolution in the frequency domain of the individual Fourier Transforms