14.7 (a) Given the control system in Figure P14.7: with the transfer functions given by: 5e-8 g(s) = 15s +1 1 8,(s) 3s + 1 8c(s) = K (1+3s) determine the largest value of K for which the control system is stable. (b) For the same control system indicated in Figure P14.7, if now, g,(s) = 1, and the plant, given as a second-order system, with the usual transfer function: g(s) = K T + 25ts + 1 Figure P14.7. y