%
% Figure 12.5
%
clf
num1=9
den1=[1 1 9]
num2=9
den2=[1 6 9]
num3=9
den3=[1 12 9]
t=0:0.01:12;
step(num1,den1,t)
hold
step(num2,den2,t)
step(num3,den3,t)
text(1.5,1.4,'(a)')
text(1.1,0.8,'(b)')
text(0.8,0.4,'(c)')
print -deps fig12_5.eps