Question

(b) The characteristic equation of a control system is given by q(s)s(+4)(s+10)+K(s+3)s+5 0 Sketch the root-locus of q(s). Indicate clearly the asymptotes, the centroid, the break-away/break-in points and the crossing of the ja-axis, if any. Hence or otherwise, determine whether the characteristic equation can have complex conjugate roots for certain values of K> 0. (Hint: 0 does not yield real roots.) dK ds (8 Marks)

Hi, the part which i am not sure is , why when finding the break in /away point the result will not yield real roots?

Answer 1