Sketch the root locus plot for the following char. eq.: s(s+1)(s+2) + k(s + 3) = 0 . Discuss the effect of adding pole at the origin on the root locus, prove your answer by using example, use Matlab to plot the old and new root locus. Discuss the effect of adding zero at the origin on the root locus, prove your answer by using example, use Matlab to plot the old and new root locus.