一类中立型时滞微分方程的振动性

Qscillation of a Class of Neutral Delay Differential Equations

考虑中立型时滞微分方程[x(t)-r(t)r(t-τ)x(t-τ)]′+q(t)x(t-δ)=0,t≥t0.其中q∈C((t0,+∞),R+),r(t)是单调不减的正函数,τ>0,δ≥0.给出该方程振动的一个充分条件,推广和改进了已有文献的相应定理.

\ Consider the neutral delay differential equation \%′+q(t)x(t-δ)=0\ t≥t\-0.\% The sufficient condition under which every solution of the equation is oscillation are given and some known results are improved.