The Nyquist polar plot of a conditionally stable system is shown in Figure 5(a) for a specific gain K = Ka with the -1 point located at (a) on the

real axis. The system has no poles of G(s)H(s) in the right-half plane, where H(s) =1. As the value of K is varied (Ka, Ki, K.) the -1 point on the real axis may be located within each of the three loops: (a), (b) and (c), respectively. In each of these 3 locations of the -1 point: Find the number of roots of the system in the right-half plane and Determine whether the system is stable or unstable.