Application of three different methods to several nonlinear partial differential equations modeling certain scientific phenomena

In the first part of this thesis, the fundamental principles that are required have been provided. In the second part, a literature review is conducted in detail. In the third part, the materials and methods are explained. In the fourth part, two models are solved with three different methods and are numerically analyzed. Additionally, and most importantly, the extended rational sinh-cosh method has been modified, we think that its new version, the modified extended rational sinh-cosh method, is promising for the future for solving differential equations. In the last part, concluding remarks are given. Several new exponential, logarithmic, trigonometric, and complex function solutions for considered models are obtained by applying the improved Bernoulli sub-equation function, the extended rational sinh-cosh and the modified extended tanh function methods.