申論題

5.Consider a control system with the following loop transfer function
-∞≤K≤∞

(c)Using Nyquist criterion and Fig. 2, determine the range of K ＜0 such that the closed-loop system can be stabilized. If the system is unstable due to the range of K, find the number of closed-loop pole(s) in the right-half of s-plane.