Q3: Consider the system below, where $G_c(s) = \frac{K(s+a)}{s}$ (i.e., proportional controller), and the plant transfer function is $G_p(s) = \frac{1}{s^2+2s-4}$. (15 pts)
a) Is the plant BIBO stable without control (e.g., open loop)? Why?
b) Using error analysis, is the closed-loop system BIBO stable or BIBO unstable? Why?
c) If stable, find the total steady-state error (tracking and disturbance) when the input $r(t) = 5tu_s(t)$, and the disturbance $d(t) = 2u_s(t)$.