Answer Happy

EXERCISE 3. Compute the DTFT of the following signals, either directly or using its properties (below a is a fixed constant |a| < 1): (a) Xn = (*)"un-10 (b) 2n = n/ = n() un (c) In = (1/a)"u-n
EXERCISE 4. Consider the following pairs of signals x and y. For each pair determine if there is an LTI system for which y is the output when the corresponding x is the input. If such system exists, determine the frequency response of an LTI system with the desired behavior. If no such system exists, explain why. (a) In = ein/3 '; yn = 2ein/3 (b) Xn = (1/2)", yn = (1/4)" (c) an = (1/2)" un, Yn = (1/4)" un