Determine whether or not each of the following signals is periodic. In case a signal is periodic, specify its fundamental period. (a) x(t)=3 cos(5t +л/6) (b) x(n) 3 cos(5n+л/6) = (c) x(n) = 2exp[jn/6 – x)] (d) x(n) = cos(n/8) cos(лn/8) ===== (e) x(n) = cos(лn/2)-sin(лn/8) + 3 cos(лn/4+/3)