4. Suppose that the frequency response of a filter is given by:
a) Write the difference equation that relates the input a[n] to the output y[n].
(b) What is the output if the input is x[n] = δ [n]?
(c) If the input is of the form z[n] = Acos(ŵn + pi), for what values of w will the output y[n] be zero?(more…)