带有正负系数的两类时滞微分方程的振动

THE OSCILLATION OF DELAY DIFFERENTIAL EQUATION OF TWO CLASSES

通过构造无穷序列的方法给出了时滞微分方程 x′(t) + px (t-τ) - qx (t-σ) =0和中立型时滞微分方程 ddt[x(t) - px(t- τ) ]+ qx(t- σ) =0振动的充要条件和一些充分条件 .这些条件使用起来很方便 ,其中 。

Necessary and sufficient conditions for the oscillations of delay differential equation x′(t)+px(t-τ)-qx(t-σ)=0 and neutral delay differential equation dd t[x(t)+ px(t- τ)]-qx(t-σ)=0 are given respectively by a method of infinite series. Some more explicit sufficient conditions are given as corollaries of our main results.