The phase margin (in degrees) of a system having the loop transfer function is $$G(s)H(s) = {{2\sqrt 3 } \over {s(s + 1)}}$$

Consider the points s₁ = −3 + j4 and s₂ = −3 − j2 in the s-plane. Then, for a system with the open loop transfer function $$$G\left(s\right)H\left(s\right)=\frac K{\left(s+1\right)^4}$$$

For a second-order system with the closed-loop transfer function $$$T\left(s\right)=\frac9{s^2+4s+9}$$$ the settling time for 2% band in seconds is

If the closed-loop transfer function T(s) of a unity negative feedback system is given by $$$T\left(s\right)=\frac{a_{n-1}s+a_n}{s^n+a_1s^{n-1}+.....+a_{n-1}s+a_n}$$$ then the steady state error for a unit ramp input is