given the sequences
x1 = [2, 6, -4, 1]
x2 = [8, 0, 2, 0, -9, 0, 1, 0]
x3 = [2, 0, -8, -8, 2]
x4 = [0, 1, 5i, 0, 6i, 0]
x5 = [9, 3, 7]
plot the
1. DFT magnitude of the computed sequences in MATLAB
2. phase responses in degrees and radians against frequency and
number of samples
3. comment on the plots