questionwalk through of how to compute any of

Question

Question

Walk through of how to compute any of these would be greatly appreciated.

(a) What is DFT of a pure cosine wave cos(t) sampled at n equally spaced points on the interval [0, 2π)?

(b) What is DFT of a pure sine wave sin(t) sampled at n equally spaced points on the interval [0, 2π)?

(c) What is DFT of the sum of the two previous functions sampled at n equally spaced points on the interval [0, 2π)?