Problem 0 Determine whether or not each of the following signals is periodic. In case a signal is periodic, specify its fundamental period. (a) xa(t) = 3cos(5t +) (b) x(n) = 3cos(5n+) (c)x(n) = 2cos (cos() (d)x(n) = 2e) (e) x(n) = cos()-sin() Deohlam !