3. (14pts) The closed-loop system shown in the block diagram has two input signals R(s) and D(s) and

one output signal Y(s). Using block diagram reduction, complete the following.

R(s) +

A(s)

H₂

G₂

(a) (7pts) Find the system transfer function Y(s)/D(s).

(b) (7pts) Find the system transfer function Y(s)/R(s).

B(s)

D(s)

G₂

H₂

Y(s)