Salas S., Alvaro H.Cieza Altamirano, GilderSánchez-Chero, Manuel Jesus2025-10-232025-10-232022-07https://repositorio.unach.edu.pe/handle/20.500.14142/895In this paper, we generalize He’s frequency approach for solving the damped Du ng equation by introducing a time varying amplitude. We also solve this equation by means of the homotopy method and the Lindstedt–Poincar´e method. High accurate formulas for approximating the Jacobi elliptic function cn are formally derived using Chebyshev and Pade approximation techniques.application/pdfenginfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/4.0/Equationinfo:eu-repo/semantics/articleIn this paper, we generalize He’s frequency approach for solving the damped Du ng equation by introducing a time varying amplitude. We also solve this equation by means of the homotopy method and the Lindstedt–Poincar´e method. High accurate formulas for approximating the Jacobi elliptic function cn are formally derived using Chebyshev and Pade approximation techniques.https://purl.org/pe-repo/ocde/ford#1.01.00