Let X(e j ) = 2e j4 , < . (a) Use the

Let X(e^jω) = 2e^−j4ω, − π ≤ ω < π.

(a) Use the MATLAB functions freqzand angle to compute the phase of X(e^jω) and then plot it. Does the phase computed by MATLAB  appear linear? What are the maximum and minimum values of  the phase, how many radians separate the minimum from the  maximum?

(b) Now, recalculate the phase but after using angleuse the function  unwrap in the resulting phase and plot it. Does the phase appear  linear?