1. For the following unity feedback system Ge(s) is a PID controller and G(s) is G(s) = 1/[s(s+1)(s+4)]. a) Draw root locus curve for K, changes from zero to infinity when K=0 and Ka=0. R(S) b) Obtain the Kp, K, and Kd values of PID controller by using the 2nd Ziegler Nichols Method. c) Draw the modified root locus curve and step response. Do you have a good step response ? d) How could you improve the performance further? Show on root locus and step response curves. Ge(s) G(s) Y(s)