A Note on the Solutions of the Van der Pol and Duffing Equations Using a Linearisation Method

Table 2

Comparison of the frequency by the SLM approach with Buonomo [2] and the HAM, Chen and Liu [9].

	(SLM)𝑖	𝜀
		0.3	0.6	1.2	1.5	1.8
	2	0.9944195093	0.9781496961	0.8970288929	0.7933396502	0.7274495579
	4	0.9944198444	0.9782168788	0.9211217519	0.8871147446	0.7394634260
	6	0.9944198444	0.9782168788	0.9211220869	0.8854079093	0.8498705704
	8	0.9944198444	0.9782168788	0.9211220869	0.8854079098	0.8482341694
	10	0.9944198444	0.9782168788	0.9211220869	0.8854079098	0.8482341695
Buonomo [2]		0.9944198444	0.9782168788	0.9211220869	0.8854079098	0.8482341695
(HAM [9])
	10	0.9944198397		0.8855524710		0.8485246885
	20	0.9944198444		0.8854094218		0.8482487089
	50	0.9944198444		0.8854079098		0.8482341635
	100	0.9944198444		0.8854079098		0.8482341695