For the above system $($assume that system is linear$)$ the main input R$($s$),$ the

disturbance $T_d(s)$ and the noise $N(s)$ are all unit step functions.

a$.$ Obtain $Y\frac{s}{R}(s),Y\frac{s}{T_d}(s)$ and $Y\frac{s}{N}(s)$

b$.$ Obtain the steady state error caused by a unit step input of $T_d(s)$