具有变系数的2n+1阶中立型微分方程正解的存在性

Existence of Positive Solutions for 2n+1 Order Neutral Differential Equations with a Minor Variable Coefficient

本文利用 Ｋｎａｓｔｅｒ不动点定理，Ｌｅｖｉ引理，给出具有变系数 Ｐ（ｔ）的 ２ｎ＋ １阶中立型微分 方程［ｘ（ｔ）－ｐ（ｔ）_ｘ（ｔ－２）］^（２ｎ＋１）＋ｆ（ｔ，ｘ（ｔ－τ_１（ｔ）），…，ｘ（ｔ－τ_ｍ（ｔ））＝０正解存在的几个充分 条件．本文结果部分地回答了文２１提出的问题．

In this paper, by Using the Knaster fixed Point theorem the levi lemma, we have given come sufficient of existence of positive solutions for 2n + 1 order neutral differential equations With n is a nonnegtive ingeger and P(t) is a voriable Coefficient. The results obtained answer partially an open problen in [1].