n阶中立型时滞方程衰减正解的存在性

ON THE EXISTENCE OF ASYMPTOTICALLY DECAYING POSITIVE SOLUTIONS OF nTH ORDER NEUTRAL DIFFERENTIAL EQUATIONS

研究了ｎ阶中立型方程正解的存在性，在ｐ（ｔ）常号和变号的情况下，给出了（＊）存在衰减正解的充分条件．特别，这些结果推广了文［２］，［４－６］和［８—１２］的有关结果．

The existence of positive solutions of nib order neutral differential equation is investigated. Some sufficient conditions are given for existence of positive solutions with asymptotic decay of (*) for the case of constant sign and nonconstant sign of coefficients. In particular the result obtained provides an extension of those in [2], [4]-[6] and [8-12].