具有正负系数的一阶中立型时滞微分方程的振动性

Neutral delay differential equations with positive and negative coefficents

得到了具有正负系数的一阶中立型时滞微分方程一切解振动的新的充分条件∫t0∞[P(s)-Q(s-τ+δ)]exp1μ∫t0∞u[P(u)-Q(u-τ+δ)]duds=∞.应用此条件得到了这类方程振动的一些较弱的充分条件.

A new sufficient conditions for the oscillation of all solutions of the first order neutral delay differential equations with positive and negative coefficients is obtained as follows：∫^∞t0[P（s）-Q（s-r＋δ）]exp（^1-μ∫^∞t0u[P（u）-Q（u-τ＋δ）]）duds=∞By using this condition, another weaker sufficient conditions are also obtained.