Note: for all continuous time signals x(t), time t = R; for all discrete time signals x[k], time index k Z. For each of the following signals, determine the Nyquist frequency and design a minimum sampling rate ensuring that the underlying analog signal can be perfectly reconstructed from the sampled signal. (a) x1(t) = 5 cos(2000t) + 10 sin(3600t) (b) x2(t) = 4 sin (100t) (c) x3(t) = sinc (110) (d) x(t) = 0.2 sinc(0.1t) cos(200t) (e) x(t) = rect(t)