% Problem 6.4
t=0:0.1:10;
disp('System 6.3(a)')
num1=5;
den1=[1 2 2];
printsys(num1,den1,'s')
[y1,x1]=step(num1,den1,t);

disp(' ')
disp('System 6.4')
num2=[5 5];
den2=[1 2 2];
printsys(num2,den2,'s')
[y2,x2]=step(num2,den2,t);

plot(t,y1,'--',t,y2,'-')
grid
xlabel('t [sec]')
ylabel('unit step responses')