Existence of nonoscillatory solutions of higher-order neutral differential equations with positive and negative coefficients Original Research Article

In this paper, we consider the following higher-order neutral functional differential equations with positive and negative coefficients: View the MathML source[x(t) + cx (t − τ)] + (−1)n+1 [P(t) x (t − σ) − Q (t) x (t − δ)] = 0, t ≥ t0, where n ≥ 1 is an integer, c ϵ View the MathML source, τ, σ, δ ϵ View the MathML source+, and P, Q ϵ C([t0, ∞), View the MathML source+), View the MathML source+ = [0, ∞). We obtain the global results (with respect to c) which are some sufficient conditions for the existence of nonoscillatory solutions.