TY - JOUR ID - 610 TI - Periodic solutions of fourth-order delay differential equation JO - Bulletin of the Iranian Mathematical Society JA - BIMS LA - en SN - 1017-060X AU - Balamuralitharan, S. AD - SRM UNIVERSITY, Y1 - 2015 PY - 2015 VL - 41 IS - 2 SP - 307 EP - 314 KW - Fourth-order delay differential equation KW - periodic solutions DO - N2 - In this paper the periodic solutions of fourth order delay differential equation of the form $\ddddot{x}(t)+a\dddot{x}(t)+f(\ddot{x}(t-\tau(t)))+g(\dot{x}(t-\tau(t)))+h({x}(t-\tau(t)))=p(t)$  is investigated. Some new positive periodic criteria are given.   UR - http://bims.iranjournals.ir/article_610.html L1 - http://bims.iranjournals.ir/article_610_0669d6cfade607a09955798000b786fb.pdf ER -