$2.(25$ points$)$

Consider the unity$-$feedback system whose open$-$loop transfer function is

$()=22$

$(2+2)(2+8)$

a$.(5$ points$)$ What is the magnitude expression of the open$-$loop transfer function?

b$.(5$ points$)$ What is the phase angle expression of the open loop transfer function?

c$.(5$ points$)$ Estimate the gain and phase crossover frequencies. Show relevant

equations$/$work