clear; close all; s=tf('s'); G=4/(s^2+5*s+4) k=[0,0.1,0.3,9/16,1,2,10]; figure; hold on; t=0:0.01:5; for i=1:7; G1=k(i)*G/(1+k(i)*G); lamG1_1(i)=(-5+(25-16*(1+k(i)))^0.5)/2 lamG1_2(i)=(-5-(25-16*(1+k(i)))^0.5)/2 kp(i)=4*k(i)/4; err(i)=1/(1+kp(i)) step(G1,t); end figure; rlocus(G);