a. Obtain the transfer functions X(s)/F(s) and Y(s)/F(s) for the following model:
4 = y
 = f(t) - 3y - 12x
b. Compute τ, (, ωn, and ωd for the model.
c. If f(t) = us(t), will the responses x(t) and y(t) oscillate? If so, compute the radian oscillation frequency, and estimate how long it will take for the oscillations to disappear.
d. Suppose that f(t) = us(t) and x(0) = (0) = 0. Obtain x(t) and y(t).