Suppose
is a circular Gaussian random variable whose PDF is described by Equation,

(a) Find the PDF of the magnitude,
for the special case when 
(b) Find the PDF of the magnitude
for the general case when 
(c) For the case when
show that the PDF of the phase angle is well approximated by a Gaussian PDF. What is the variance of the Gaussian PDF that approximates the PDF of the phase angle.