The loop gain function of a feedback system is described by
![1163_Function 4.jpg](https://secure.tutorsglobe.com/CMSImages/1163_Function%204.jpg)
(a) Determine the frequency f180 at which the phase of T ( f ) is -180 degrees.
(b) For β = 0.019, (i) find |T ( f180)| and (ii) find the phase at which |T | = 1.
(c) Using the results of part (b), determine the low-frequency closed-loop gain Af (0).