Oscillation of higher-order nonlinear delay differential equations with oscillatory coefficients

Abstract

A criterion is established on the bounded solutions of type higher-order nonlinear neutral differential equations of type oscillatory or tending to zero at infinity [a(t) [x(t)+r(t)x(\kappa(t))]^{(n-1]' +p(t)F(x(\tau(t)))+q(t)G(x(\sigma(t)))= \phi(t), where t\geq t_0, n\geq 2, a,p are positive, r,q,\phi are allowed to alternate in sign infinitely many times, F,G are continuous functions, and \kappa,\tau,\sigma are strictly increasing unbounded continuous delay functions.