GATE EC 1999 Set 1 Q2.14 — Control Systems

If the closed-loop transfer function $T(s)$ of a unity negative feedback system is given by
$$\mathrm{T}(\mathrm{s})=\frac{a_{n -1} \mathrm{~s}+a_{n}}{\mathrm{~s}^{n}+n_{1} s^{n-1}+\ldots+a_{n-1} s+a_{n}}$$
then the steady state error for a unit ramp input is