Abstract
In this study, we construct the new solitary wave solutions for two well known nonlinear wave equations whose describe the wave propagation in nonlinear media. We implemented a new technique which is extension of modified rational expansion method on nonlinear three-dim modified Kortewege–de Vries Zakharov–Kuznetsov and extended Zakharov–Kuznetsov equations. The new results are elliptic, hyperbolic, trigonometric, rational type which are representing to solitary waves, periodic waves, traveling waves, kink-antikink solitons, dark-bright solitons. The physical behavior of some calculated results represented graphical by using the software Mathematica. The determined results are new, more general and have numerous applications in the area of nonlinear sciences including nonlinear plasma, fiber optics, mechanics, quantum physics, laser physics, fluid physics, engineering and other types of physical sciences. The demonstrated results show that new technique is efficient, fruitful, powerful and reliable to study analytically different types of higher order complex NLPDEs arises in various types of applied sciences.