3) Find the Fourier transform of the following signals (Hint: use FT properties and FT pairs) (20...

3) Find the Fourier transform of the following signals (Hint: use FT properties and FT pairs) (20 points) Xi(t X3(t) 个 X2(4) 201个 '구 4) Let fi(l) and f5() be signals whose FT are depicted in the figure below. Also consider the signal P (1)-cosa, p2(1) = cos a,r. (Hint: use FT properties) a. Find and sketch x1(t)- e-jat fi (t) + 2e-jbt f2(t) b. Find and sketch x2 (t)- afi(bt) c. Find and sketch the FT o#x (1) = f(t)A(1) d. Find and sketch the FT orn (1)-0 +At))Ps(t). (30 points)