Oscillation criteria for a class of second-order neutral delay differential equations

摘要

In this article, we investigate oscillation and asymptotic behaviour of all solutions of a class of neutral delay differential equations of second-order with several positive and negative coefficients haling the form,where R, P, Q are bounded beginning segments of positive integers, p_i q_i ∈ C([t_0,∞), R~+),α_i,β_iγ_i∈C([t_o,∞ ),R), are delay functions and fis a continuous function. Our results improve and extend the recent results given in the papers [J. Manojlovié, Y. Shoukaku, T. Tanigawa, N. Yoshida, Oscillation criteria for second-order differential equations with positive and negative coefficients, Appl. Math. Comput. 181 (2006) 853-863] and [A. Weng, J. Sun, Oscillation of second order delay differential equations, Appl. Math. Comput. 198 (2) (2008) 930-935].