A hybrid method for a polynomial complex zero

Abstract

Using classical Weierstrass' result concerning polynomial zeros in a suitable interval form and some iterative method in floating-point arithmetic, a hybrid method for finding an isolated simple complex zero of a polynomial is established. This method possesses a high computational efficiency and the capability of automatic determination of error bounds of the approximate solution. A computationally verifiable test for the existence of a polynomial complex zeros in a given disk is also presented. © 1991.