(in lingua inglese)
A generalized Legendre wavelet operational matrix of derivative is used to solve the Duffing equation involving both integral and non-integral forcing terms. This operational matrix method together with Gaussian quadrature formula reduces the given system into a system of algebraic equations. Solution obtained by this method and comparison with the recently proposed methods reveals that the proposed LWOM method is a very effective and convenient method to solve Duffing equations. Moreover the proposed method is very simple, easy to implement and is able to approximate the solution more accurate in the given interval.