A signal x1(t) = 5 sin(20πt) is sampled at four times its Nyquist rate. Another signal x2(t) = 5 sin(2πf0t) is sampled at the same rate. What is the smallest value of f0 which is greater than 10 and for which the samples of x2(t) are exactly the same as the samples of x1(t)?  A signal x(t) = 4 cos(200πt) −7 sin(200πt) is sampled at its Nyquist rate with one of the samples occurring at time t = 0. If an attempt is made to reconstruct this signal from these samples by ideal sinc-function interpolation, what signal will actually be created by this interpolation process