The signal flow graph of a system is shown in figure. The transfer function $$\frac{C(s)}{R(s)}$$ of the system is

A second-order system has the transfer function $$\frac{C\left(s\right)}{R\left(s\right)}=\frac4{s^2+4s+4}$$. With r(t) as the unit-step function, the response c(t) of the system is represented by

The open-loop transfer function of a unity feedback system is $$$G\left(s\right)=\frac k{s\left(s^2+s+2\right)\left(s+3\right)}$$$ the range of 'k' for which the system is stable

The root locus of the system $$$G\left(s\right)H\left(s\right)=\frac K{s\left(s+2\right)\left(s+3\right)}$$$ has the break-away point located at