e8p21.m

% Example 8.21
G = tf([1],[1 2 1 0]);
T1 = G/(1+G); T2 = 0.5*G/(1+0.5*G);
   bode(T1), hold on
   bode(T2), hold off, pause
t = 0:0.5:20;
   step(T1,t), hold on
   step(T2,t), hold off