Is the continuous-time signal x(t) = sin(3πt/5) periodic? If yes, what is the fundamental period?

What is the Fourier series coefficients a-1 of the periodic signal x[n] = cos(πn/4 – π/5) with period N = 8? 

What is the Fourier transform H1(jω) of h1(t) = 2cos(5t)?

For a continuous-time signal y(t) = x1(t)x2(t) (multiplication), assume the Fourier transform of x1(t) is X1(jω) and the Fourier transform of x2(t) is X2(jω), what is the Fourier transform Y(jω) of y(t)? 

For a LTI system with impulse response h(t) = e2t u(3-t), is the system causal?

Consider a continuous-time LTI system for which the input x(t) and output y(t) are related by the differential equation 

A high variation in pixel values in a homogeneous phantom is a measure of _____.

The CT scanner must be calibrated so that _____ is at CT number zero.

Each sweep of the source-detector around the body during CT is called a _____.

The use of repeat analysis in a radiographic imaging department provides pertinent direction for