Using the message signal m(t) = t/1 + t^2 determine and sketch the modulated wave for amplitude modulation whose percentage modulation equals the following values: 50 percent 100 percent 125 percent Consider the DSB-SC modulated wave obtained by using the sinusoidal modulating wave m(t) = A_m cos(2 pi f_m t) and the carrier wave c(t) = A_c cos(2 pi f_c t + phi) The phase angle phi, denoting the phase difference between c(t) and m(t) at time t = 0, is variable. Sketch this modulated wave for the following values of phi: phi = 0 phi = 45 degree phi = 90 degree phi = 135degree Consider a composite wave obtained by adding a noncoherent carrier A_c cos(2 pi t_c t + phi) to a DSB-SC wave cos(2 pi f_c t)m(t). This composite wave is applied to an ideal envelope detector. Find the resulting detector output for phi = 0 phi notequalto 0 and |m(f)|