Q$3$: consider the closed loop control system with PD$-$controller as shown.

$($a$)$ Find the values of the controller parameters $K_1$ and $K_2$ such that the close$-$loop poles of the transfer function must have a damping ratio $=0\mathrm{.}7,$ and a natural frequency ${}_n=10ra\frac{d}{s}.$

$($b$)$ Based on the results obtained in part b$,$ Compute the steady state error for unit step input

$($c$)$ How can you make the error for step input to be equal to zero?