A loop gain function is given by
(a) Determine the frequency f180 (to a good approximation) at which the phase of T( f ) is -180 degrees.
(b) What is the magnitude of T( f ) at the frequency f = f180 found in part (a)?
(c) Insert a dominant pole such that the phase margin is approximately 60 degrees. Assume the original poles are fixed. What is the dominant pole frequency?