A NEW TWO STEP CLASS OF METHODS WITH MEMORY FOR SOLVING NONLINEAR EQUATIONS WITH HIGH EFFICIENCY INDEX

It is attempted to extend a two-step without memory method to it's with memory. Then, a new two-step derivative free class of without memory methods, requiring three function evaluations per step, is suggested by using a convenient weight function for solving nonlinear equations. Eventually, we obtain a new class of methods by employing a self-accelerating parameter calculated in each iterative step applying only information from the current and the previous iteration, defining a with memory class. Although these improvements are achieved without any additional function evaluations, the R -order of convergence are boosted from ۴ to ۵.۲۴ and ۶, respectively, and it is demonstrated that the proposed with memory classes provide a very high computational efficiency. Numerical examples are put forward and the performances are compared with the basic two-step without memory methods.

Keywords:

Nonlinear equation , With memory method , R-order of convergence , self-accelerating parameter