Control Systems - Steady State Error

In the feedback control system shown in the figure below $G(s) = \frac{6}{s(s+1)(s+2)}$. $R(s), Y(s)$, and $E(s)$ are the Laplace transforms of $r(t), y(t)$, and $e(t)$, respectively. If the input $r(t)$ is a unit step f...

A closed loop system is shown in the figure where k > 0 and α > 0. The steady state error due to a ramp input (R(s) = α/s²) is given by