Mathematics and Computer Applications - Sciene

The objective of this thesis studying and deriving with some modification as a new approach of Runge-Kutta method including explicit, semi-explicit and implicit methods as well as studying stability of convergence of these methods. Also, one of most important themes of the thesis is to introduce variable step size and variable order methods using an extrapolation method which has the utility of controlling the local truncation error to be less than a prespecified tolerance error.