3 command

>> Untitled3b

H2 =

       0.03 s^4 - 0.02 s^3 + 0.01 s^2
  -----------------------------------------
  s^4 - 2.8 s^3 + 3.02 s^2 - 1.468 s + 0.27

Continuous-time transfer function.


Points1 =

     0

unstable system

r =

sum((2202*r3*r3^n - 405*r3^n - 4030*r3^2*r3^n + 3200*r3^3*r3^n)/(140000*r3^3 - 302000*r3^2 + 220200*r3 - 54000), r3 in RootOf(z1^4 - (14*z1^3)/5 + (151*z1^2)/50 - (367*z1)/250 + 27/100, z1))