Senol, MDolapçi, ITAksoy, YPakdemirli, M2024-07-182024-07-181085-33751687-0409http://akademikarsiv.cbu.edu.tr:4000/handle/123456789/5766The previously developed new perturbation-iteration algorithm has been applied to differential equation systems for the first time. The iteration algorithm for systems is developed first. The algorithm is tested for a single equation, coupled two equations, and coupled three equations. Solutions are compared with those of variational iteration method and numerical solutions, and a good agreement is found. The method can be applied to differential equation systems with success.EnglishNONLINEAR OSCILLATORPERIODIC-SOLUTIONSAPPROXIMATIONSEXPANSIONFORCEArticle