Eight and ninth-order convergence iterative structures for obtaining nonlinear equations solution O. Ogbereyivwe, S. A. Ogumeyo, E. J. Atajeromavwo Journal of Interdisciplinary Mathematics, 2024 An eighth and ninth-order fast convergence iterative structures for determining the solution of nonlinear equations is put forward in this manuscript. The iterative structures are modification of a three-step variants of the Newton method via the use of the divided deference and weight functions. The computational iterative structures possess the advantages that they, do not require evaluation of higher derivative and converge faster than compared iterative structures with same convergence order. The convergence analysis of the iterative structures was established via the method of Taylor series. The computational results obtained with the developed iterative structures are juxtaposed with those obtained from some contemporary existing methods, and they performed better in terms of fast convergence.
Family of optimal two-step fourth order iterative method and its extension for solving nonlinear equations Oghovese Ogbereyivwe, Veronica Ojo-Orobosa Journal of Interdisciplinary Mathematics, 2021 In this paper, the weight function technique is utilized to develop new family of two-step fourth order convergence iterative methods for approximating the solution of nonlinear equations. The methods require the evaluation of three distinct functions evaluation per iteration circle and as such, are optimal in agreement with the Kung-Traub’s conjecture. This developed family of methods is further extended to design another new family of four-step ninth order convergence with efficiency index EI = 1.5518. We carried out the convergence analysis of the two families of iterative methods. This analysis provided us with information about the flexibility of the weight function in the method used in constructing other new families of iterative methods. The methods are applied to solve some nonlinear equations and real life problems that are modeled into nonlinear equations. The results obtained from computation experience are compared with some of its existing contemporary methods.