Will give thumbs up. Thank You

3. Modify tf_demo.m to do the following: a) Use the tf() function to define a system variable for: X+4.3 + 6.8 + 8x = f(t) Use the step() function to plot the response of the system for f(t) = u(t) (a unit step). 2 - CURRENT FOLD num = [1]; den=[1 4 20); I sys=tf(num, den); 3 4 - % 1/(s^2 + 4s + 20) 5 step(sys) %very powerful and easy to use pause 7 8 9 WORKSPACE impulse(sys) % also powerful and easy to use pause 10 11 12 = 0:0.1:20; u = 3* sin(t); % vector of time samples % the INPUT valuse 13 14 15 1sim(sys, u, t) %plot the response and the input pause 16 17 18 y=lsim(sys,u,t); plot(t,y); 19