I will upvote if u can solve all of them

4. Decide whether following signals are periodic or not. If it is periodic, find the fundamental period. Draw the graph of the signals and their spectrum (magni- tude and phase w.r.t frequency separately) using Python 3.6 and libraries Numpy, Scipy, matplotlib and vispy. (a) cos (2mt) (b) (t)et (c) 1 + 5 cos(2257nt + /4) + 2 cos(244Ort + 3/2)