The best members of the Kim family, in terms of stability, are obtained by using complex dynamics. From this elements, parametric iterative methods with memory are designed. A dynamical analysis of the methods with memory is presented in order to obtain information about the stability of them. Numerical experiments are shown for confirming the theoretical results.
KEYWORDSbasin of attraction, iterative methods with memory, low-dimensional dynamical systems, nonlinear algebraic or transcendental equations, parameter plane, stability
MSC CLASSIFICATION
65H05
INTRODUCTIONTo find a solution of the nonlinear equation f(x) = 0 is a common problem that appears frequently in different fields of science and engineering. These nonlinear problems require iterative methods to be solved. In the last decades, there has been an extensive literature focused on the generation of iterative procedures to find a solution . We can see a good overview on classical and recent results in Amat and Busquier 1 or Petković et al. 2 The iterative methods are fixed-point schemes that, starting from one or more initial estimations, obtain a new value that approaches our solution asIf we use only the last iteration (p = 0), we have an iterative method without memory and, if we use more than one previous iterations (p > 0), the iterative scheme is with memory.Related with the order of convergence of iterative methods without memory, the Kung-Traub conjecture 3 establishes that the order of a scheme without memory is always lower than 2 d−1 , where d is the number of functional evaluations per iteration. When this bound is reached, the iterative method is called optimal. One technique for improving the order of convergence without increasing the number of functional evaluations is to introduce memory in the scheme, that is, the new iterate depend on more than one previous iterates.