K(s + 3) T(S)=s4+7s3+14s2+(8+K)s+3K (8.40) Using the denominator and simplifying some of the entries by multiplying any row by a constant, we obtain...

Can someone explain how to find the intersection of root locus and imaginary axis from routh table? Why do we use s^2 row to solve for the intersection? What is even polynomial mean in this problem? It means even function? the polynomial has even number of term ?or the highest order term in the polynomial is even?