Modified Variational Iteration Method for Sine-Gordon Equation

In this paper, we introduce a modified variational iteration method for solving nonlinear differential equations. The main advantage of this modification is that it gives stable and relatively accurate results while increasing the domain of unknown function in differential equation, where variational iteration method becomes unstable. The proposed method is based on Chebyshev polynomial approximations in the correction functional of variational iteration method. To show the advantages of the proposed method, we use the sine-Gordon equation as a test problem.