Addendum to "On the stability properties of polynomials with perturbed coefficients"

This note serves to point out that the method presented by Soh et aL [1] can be used to obtain the largest hypersphere which contains the coefficients of polynomials which have zeros only on or within any simply connected region in the complex plane which is symmetric with respect to the real-axis. It is then extended to obtain the largest right circular hypercone which contains the coefficients of polynomials which have zeros only on or within any simply connected region .