Rasedee, AFNAFNRasedeeIshak, NNIshakHamzah, SRSRHamzahIjam, HMHMIjamSuleiman, MMSuleimanIbrahim, ZBZBIbrahimSathar, MHAMHASatharRamli, NANARamliKamaruddin, NSNSKamaruddin2024-05-292024-05-2920171742-65961742-658810.1088/1742-6596/890/1/012045WOS:000423857800045https://oarep.usim.edu.my/handle/123456789/12167Nonlinear phenomena in science and engineering such as a periodically forced oscillator with nonlinear elasticity are often modeled by the Duffing oscillator (Duffing equation). The Duffling oscillator is a type of nonlinear higher order differential equation. In this research, a numerical approximation for solving the Duffing oscillator directly is introduced using a variable order stepsize (VOS) algorithm coupled with a backward difference formulation. By selecting the appropriate restrictions, the VOS algorithm provides a cost efficient computational code without affecting its accuracy. Numerical results have demonstrated the advantages of a variable order stepsize algorithm over conventional methods in terms of total steps and accuracy.en-USArticle890