4) Consider the continuous-time signal x(t)=5cos(8t) which is sampled eight times, starting at t=0, at a sample period of T,=0.1 seconds, to generate the digital signal x[n]. a) Compute (by hand) the DFT of the digital signal x[n]. b) Confirm the results of part a) using Matlab. c) Compute the Fourier Transform X(jo) of the original continuous-time signal x(t). Compare it with the results above (in a),b)) and explain any differences