Oscillation Criteria For Solutions Of Delay Differential Equations

In this paper, we mainly study the oscillation properties of second-order delay differential equations, third-order delay differential equations and third-order neutral delay differential equation. And some oscillation criteria will be given. This article will be divided into four chapters.In chapter 1, we mainly introduce the differential equations of the domestic and foreign research present situation, the significance of selected topic, the main work of this article and a several basic concepts on the oscillation of delay differential equations.In chapter 2, we consider the second-order delay differential equationThe oscillation theorems will be given in the case of .At the same time, the theorems extend the criteria in [ ]32.In chapter 3, we mainly discuss the third-order delay differential equation with two parametersThe oscillation criteria will be given in the case of 0 ?p?t? ?1, the oscillation conclusion further promote the conclusions in the literature ?38?.In chapter 4, we mainly elaborate the third-order nonlinear neutral delay differential equation with two parametersSome new oscillation theorems will be given in the case ofThe theorems extend the oscillation criteria in?15?.