% Problem 7.8
A=[0 1 0 0 0 0
-85.239 -5 13.874 0 0 0
0 -352.8 -13.3 1020 0 0
0 0 0 0 1 0
0 0 0 0 0 1
0 0 0 0 -0.000156 -125];

B=[0; 0; 0; 0; 0; 1560];

C=[1 0 0 0 0 0];

D=0;

[num,den]=ss2tf(A,B,C,D,1);
for j=1:length(num),
    if abs(num(j))<1.e-7
       num(j)=0;
    end
end
printsys(num,den,'s')
[p,z]=pzmap(num,den)
rlocus(num,den)
grid