Exact solutions of nonlinear evolution equations with modified extended Tanh function and new Kudryashov methods

Nonlinear evolution type equations are equations used to model natural phenomena, physical processes or other complex phenomena. The importance of these equations derives from their ability to better reflect real-world complexity and interactions. Therefore, the importance of finding the exact solutions of these equations is that it helps us to understand and predict the behavior of these equations in more detail. The aim of this thesis study; trying to find new exact solutions of (3+1)-dimensional nonlinear evolution type equations with modified extended tanh function and new Kudryashov methods, identifying solution types to better understand the physical behavior of the solutions found and to bring new exact solutions to the literature by visualizing the movements of these solutions with the help of the Maple software. In this thesis, in the (3+1) dimensional nonlinear evolution type equations; the exact solutions of (3+1)-dimensional potential Yu-Toda-Sasa--Fukuyama equation, (3+1)-dimensional Boussinesq equation and more general the (3+1)-dimensional Nizhnik Novikov Veselov equation have been examined with the modified extended tanh method and their exact solutions have been brought to the literature. In addition, the exact solutions of the (3+1)-dimensional potential Yu-Toda--Sasa--Fukuyama equation and more general the (3+1)-dimensional Nizhnik Novikov Veselov equation with the new Kudryashov method have been examined and their exact solutions have been brought to the literature. Keywords: Nonlinear Evolution Equations, Exact Solutions, Modified Extended Tanh-Function Method, New Kudryashov Method