Oscillation Results for Fourth-Order Nonlinear Neutral Differential Equations with Positive and Negative Coefficients

Abstract

Unbounded oscillation and asymptotic behaviors of a class of nonlinear fourth-order neutral differential equations with positive and negative coefficients of the form (r(t)(y(t)+p(t)y(t-τ))(Formula Presented) and (Formula Presented) are investigated under the assumption that (Formula Presented) for various ranges of p(t). Sufficient conditions are obtained for the existence of positive bounded solutions of (E). © 2013 Springer Science+Business Media New York.