Suppose that the signals x[n], x[n] and x3[n] are given by x[n] = cos (2n). x2[n] = sin( 2n 25 and x3[n] = 2/20 (a) Determine whether x[n] is periodic. If so, determine the number of samples per fundamental period. (b) Determine whether x[n] is periodic. If so, determine the number of samples per fundamental period. (c) Determine whether x3[n] is periodic. If so, determine the number of samples per fundamental period. (d) Determine whether the sum of x[n] x[n], and x3[n] is periodic. If so, determine the number of samples per fundamental period.