Solution: 10.8.6.3 Wehave GH(s)= K s 2 (s+10) The Bode phase and magnitude plots are shown in Figure 1 In this case both gain margin and phase 10 -2 10 -1 10 0 10 1 10 2 10 3 -80 -60 -40 -20 0 20 10 -2 10 -1 10 0 10 1 10 2 10 3 -250 -200 -150 -100 Figure 1: Bode phase and magnitude plots of GH margin can both be good indicators. The root locus plot, shown in Figure 2, con rms this. We can achivegood damping ratios for the proper choice of gain, meaning that wewillsimultaneously havegood phase margin and good gain margin. As we increase the gain both phase margin and gain margin decline, so wewould hvetosaythat in this case both are of equal value in assessing stability.This is the usual case, and one reason whywecanrelie so heavily on phase margin in our designs in chapter 11. -10 -8 -6 -4 -2 0 2 4 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 Real Axis Imag Axis Figure 2: Root locus