4. Using the nyquist function, obtain the Nyquist plot for the following transfer functions: R(s) 2 Time delay 2-ST s100 8 S Figure 4 1 s+2 Y(s)/n10 s+10' 48 = s²+8s+24'

10 (a) G(s) (b) G(s) (c) G(s) = = = s3+3s2+3s+1* Figu