# IJPAM: Volume 55, No. 3 (2009)

EXISTENCE OF PERIODIC SOLUTIONS FOR -TH
ORDER DIFFERENTIAL EQUATIONS WITH
DEVIATING ARGUMENT

Xing Rong Chen, Li Jun Pan
Department of Mathematics
Jia Ying University
Meizhou, Guangdong, 514015, P.R. CHINA
e-mail: cxrgd@tom.com
e-mail: plj1977@126.com

Abstract.By employing the coincidence degree theory of Mawhin, we study the existence of periodic solutions for -th order differential equations with deviating argument . Some new results on the existence of periodic solutions of the equations are obtained. Our work generalizes the known results.