On oscillation of second order neutral type delay differential equations

摘要

Oscillation criteria are obtained by using the so called H-method for the second order neutral type delay differential equations of the form(r(t)ψ(x(t))z′(t))′+q(t)f(x(σ(t)))=0,t⩾t0,where z(t)=x(t)+p(t)x(τ(t)), r, p, q, τ, σ, ∈C([t0,∞),R) and f,ψ∈C(R,R).The results of the paper contains several results obtained previously as special cases. Furthermore, we are also able to fix an error in a recent paper related to the oscillation of second order nonneutral delay differential equations.