The block diagram of a feedback control system is shown in Figure P8.12 (a).The transfer functions of the blocks are represented by the frequency response curves shown in Figure P8.12 (b). (a) When G3 is disconnected from the system, determine the damping ratio ζ of the system, (b) Connect G3 and determine the damping ratio ζ. Assume that the systems have minimum phase transfer functions.
