Solving equations of the form H(x)=0 is one most faced problem in mathematics and other science fields such as chemistry or physics. This kind cannot be solved without use iterative methods. The Steffensen-type methods, defined using divided differences are derivative free, usually considered to solve these problems when H a non-differentiable operator due its accuracy efficiency. However, gene...

Dolores M. Cortez, Marc D. Feldman, Srinivas Mummidi, Anthony J. Valente, Bjorn Steffensen, Matthew Vincenti, Jeffrey L. Barnes, and Bysani Chandrasekar Department of Veterans Affairs South Texas Veterans Health Care System, and Departments of Medicine and Periodontics and Biochemistry, University of Texas Health Science Center, San Antonio, Texas; and Department of Medicine, Dartmouth Medical ...

E. G. Steffensen, V. Prakash, S. F. Eskildsen, K. Vestergård, V. V. Iyer, and E-M. Larsson Department of Radiology, Aalborg Hospital/Århus University Hospital, Aalborg, Denmark, Department of Nuclear Medicine, Aalborg Hospital/Århus University Hospital, Aalborg, Denmark, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark, Department of Neurology, Aalborg Hospital/...

In this article we study Steffensen method to solve nonlinear matrix equation $X+A^T X^{(-1)}A=Q$, when $A$ is a normal matrix. We establish some conditions that generate a sequence of positive denite matrices which converges to solution of this equation.

In the study of systems’ dynamics presence symmetry dramatically reduces complexity, while in chemistry, plays a central role analysis structure, bonding, and spectroscopy molecules. more general context, principle equivalence, local symmetry, dictated gravity, space-time itself. certain instances, especially we end up having to deal with an equation multiple roots. A variety optimal methods ha...