Please graph the spectrum using only MATLAB and provide the code used! Only do part B). Thank you! D-C.5 The following signal is the product of a sinusoid and a finite Fourier series: x(t)=sin(7t)(k=33 2+jk3ejkt) (a) Explain why the term in parentheses is real-valued. (b) Use the frequency shifting property to make a sketch of the spectrum of the signal defined above..