a) Consider the sequence; y(n) = 8(n)- 48(n-1) + 28(n 2) 58(n 4) [5] - - Find the four-point DFT of y(n). -n b) A filter is defined by y[n] = (j)" +(j), N = 5 determine the impulse response of y[n] and use it to compute the frequency response and its corresponding magnitude.