Draw a Nyquist diagram for each of the following systems, and compare the result with that obtained using the MATLAB command Nyquist.

(a)

(b)

(c)

KG(s) = K(s + 2) s + 10 K

KG ( s) = ..,---.,...,---:-:c-

(s + 10)(s + 2) 2 KG(s) = K(s + 10)(s + 1)

(s + lOO)(s + 2)3 Using the plots, estimate the range of K for which each system is stable, and qualitatively verify the result using root locus plot (generated by hand or using 1\!IATLAB).

Problem