New approach method for solving Duffing-type nonlinear oscillator

Results are presented for different values of amplitude vibration of the problem parameters which would certainly illustrate that this method (AGM) is efficient and has enough accuracy in comparison with other semi analytical and numerical methods. Moreover, results demonstrate that AGM could be applicable through other methods in nonlinear problems with high nonlinearity. Furthermore, convergence problems for solving nonlinear equations by using AGM appear small.