摘要
The existence of postive solutions of second order neutral differential equation.(x（t）-cx（t-r）〃+P（t）x(g（t）=0,t≥t<sub>0</sub> （*）is investigated some sufficient conditions are given for the existence of positivesolutions with asymptotic clecay of（*）for the cases of constant sign and noncon-stant sing of coefficients.It also is shown that one of these sufficient conditionsis necessasy.
The existence of postive solutions of second order neutral differential equation.(x (t)-cx(t -τ)" + P( t)x (g ( t)=0, t ≥t0is investigated some sufficient conditions are given for the existence of positive solutions with asymptotic decay of (* ) for the cases of constant sign and noncon-stant sign of coefficients. It also is shown that one of these sufficient conditions is necessary.
