The impulse response of an LTI system can be obtained by

The characteristic equation of an LTI system is given by
F(s) = s⁵ + 2s⁴ +3s³ + 6s² - 4s - 8 = 0.The number of roots that lie strictly in the left half s-plane is _____.

For the system shown in the figure, s = –2.75 lies on the root locus if K is_____.

The phase margin (in degrees) of the system G(s)=$${{10} \over {\left( {s + 10} \right)}}$$ is ___________.