Consider the real-valued passband signal xp(t) = xc(t) cos(2fct) xs(t) sin(2fct), where, as usual, xc(t) and xs(t) are real-valued baseband signals with (real) band- width W/2. Let Ec, Es, Ep represent respectively, the energies of xp(t), xc(t), xs(t). (1) Assume that fc W , show that R xc(t) cos(4fct)dt = R xs(t) cos(4fct) = 0. (2) Show that Ep = Ec/2 Es/2. Hint: Use trigonometric identities on x2 p(t)