MATLAB System Variables

Use the tf () function (modify the code given below) to define a system variable for x'''+4x"+6+x'+8x=f(t).

Use the step() function to plot the response of the system for f(t)=u(t) (a unit step)

Add comments explaining each line and state the equation solution

%Transfer Fucntion num = [1]; den=[1 4 20];

sys=tf(num,den);

step(sys) pause

impulse(sys) pause

t = 0:0.1:20; u = 3*sin(t);

lsim(sys,u,t) pause

y=lsim(sys,u,t); plot(t,y);