The characteristic equation ofthe system is q(s) = s^5+13s^4+33S^3+32s^2+20s+k^2 where k>0.
a). Find the range of values of k for which the system is stable using the Routh-Hurwitz table.
b) What value of k makes the system marginally stable?
c) Is the marginal stability due to a real pole or a complex pair? If it is due to a complex pair, find the frequency of oscillation.