For the following model the output is x and the input is f(t). x =-4x1+2x2 x2=-5x2+9f(t) a. Use MATLAB to compute and plot the free response for x (0)=3, and x2 (0)=5. b. Use MATLAB to compute and plot the unit-step response for zero-initial conditions. c. Use MATLAB to compute and plot the response for zero-initial conditions with the input f(t)=3 sin 10xt, for 0t2.