Question Four In the following control system, if Gc(s) is a PI controller and plant transfer function G(s) is given by: G(s) = 3a +95 +18 ) Gc(s) G(s) Determine: (a) The transfer function for the PI.controller in form of poles and zeros (3 marks) (b) The position of the dominant pole corresponding to a time constant of 0.25 s and damping coefficient of 0.8 (8 marks) The position of the controller zero, zo (6 marks) (d) The value of the proportional gain, Kp