Abstract
The unstable nonlinear Schrodinger equations describe the time evolution of disturbances in marginally stable or unstable media. In this paper, the extended form of simple equation method (SEM) is employed to construct exact travelling wave solutions of unstable nonlinear schroodinger equation and modify unstable nonlinear schrodinger equation. The exact solutions are obtained in the form of trigonometric, hyperbolic, exponential and rational functions in which some of them are new. The movements of these solutions are shown graphically. The computational work and obtained results show that the presented method is simple, effective and straightforward, and can be employed to many other types of unstable nonlinear evolution equations arising in mathematics, mathematical physics and other areas of applied sciences. (C) 2017 Elsevier GmbH. All rights reserved.