【摘要】 本文考虑二阶既具正系数又具负系数的时滞微分方程(x|¨)(t)+p(t)x(t-τ)-q(t)x(t-σ)=0 (*)(其中 p(t)、q(t)是[f_o,+∝)上的非负连续函数,τ、σ是正实数)的振动性。获得了方程(*)的所有有界解振动的充分性判据;以及在 p(t)、q(t)均为常数的情况下,获得了方程(1)的所有有界解振动的一些必要条件和充分必要条件。更多还原

【Abstract】 In this paper,we consider oscillation of a class of second order differe-tial-difference e(?)uationx(t)+p(t)x(t-τ)-q(t)x(t-σ)=0 (E)where p(t)≥0,q(t)≥0,τ>0,σ>0 and p(t)、q(t)continuous for t≥t_o.Wegive a sufficient condition for oscillation of all of bounded solution of (E).When p(t) and q(t) are pesitive constants,we obtain some the necessaryconditions and the necessary and sufficient conditions for oscillation of all ofbounded solutions of equ.(E)更多还原