first time on here!
I'm working through "Digital Signal Processing using MATLAB" by Vinay and Proakis. Good book.
I am stuck on this example tho.
Shouldn't the imaginary part in the denominator (magnitude calculation) be (-0.9sin(w))^2 since the Frequency Response equation has an e^-jw?
Also why does the angle calculation include a -arctan instead of just a regular arctan.