The message signal s₁(t) = sin(1007) modulates the carrier c(t) = cos(3600πt) to generate the DSB-SC AM signal. a. Sketch the spectrum of the message signal. b. Determine and sketch the spectrum of the resulting DSB-SC AM signal. Identify the upper and lower side bands in the spectrum. c. Repeat (a) and (b) for s₂(t) = cos(600mt) sin(1800mt).