OSCILLATION CRITERIA FOR A CLASS OF HIGHER ORDER NEUTRAL DIFFERENTIAL EQUATIONS

摘要

We establish a new oscillation condition for even order neutral type differential equation of the following form (x(t) + a(t)x(τ(t))]~((n))+p(t)f(t, x(t), x(τ_1(t)), ... , x(τ_m(t))) = 0, where f is continuous and exists 1 ≤ k ≤ mτ(t) = τ_k(t), a, τ_i ∈ C([0, ∞ ], R), i = 1, ... , m. such that 0 ≤ a(t) ≤ L and lim_(t→∞) τ_i(t) = ∞, i = 1, ..., m.