Given the system shown in Figure P7.23, do the following:

a. Derive the expression for the error, E(s) = R(s) - C(s), in terms of R(s) and D(s).

b. Derive the steady-state error, e (∞), if R(s) and D(s) are unit step functions.

c. Determine the attributes of G₁(s); G₂(s), and H(s) necessary for the steady-state error to become zero.

D(s) R(s) C(s) G|(s) G2(s) H(s) FIGURE P7.23 System with input and disturbance