OICC Press Journal of Theoretical and Applied Physics 2251-7235 7 1 2023 11 17 Determination of the amplitude-frequency for strongly nonlinear oscillator by two approximate analytical techniques 10.1186/2251-7235-7-38 EN OICC Press Authors Various OICC Press Authors Journal Article 2023 11 17 AbstractIn this paper, we investigate two of the analytical approximate techniques, energy balance method and amplitude-frequency formulation, and these approximate techniques are applied to solve the strongly nonlinear differential equation of a mass attached to the center of a stretched elastic wire. We present a comparative study between the energy balance method and amplitude-frequency formulation with exact solution. The approximate results reveal that these methods are very effective and convenient for determining the frequencies of nonlinear dynamical systems.