An amplifier with resistive negative feedback has two left half-plane poles in its open-loop transfer function. The amplifier

The block diagram of a feedback system is shown in Figure.
(a) Find the closed loop transfer function.
(b) Find the minimum value of G for which the step response of the system would exhibit an overshoot, as shown in Figure.
(c) For G equal to twice this minimum value, find the time period T indicated in Figure.

For the linear, time-invariant system whose block diagram is shown in Fig. with input x(t) and output y(t),
(a) Find the transfer function.
(b) For the step response of the system [i.e. find y(t) when x(t) is a unit step function and the initial conditions are zero]
(c) Find y(t), if x(t) is as shown in Fig. and the initial conditions are zero.

A system described by the transfer function $$$H\left(s\right)=\frac1{s^3+\alpha s^2+ks+3}$$$ is stable. The constraints on $$\alpha$$ and k are,