Oscillation of forced neutral differential equations with positive and negative coefficients

摘要

In the paper the forced neutral differential equation with positive and negative coeffi- cients d/df[x(t)-R(t)s(t-r)]+P(t)x(t-τ)-Q(t)x(t-σ)=f(t),t≥t_0, is considered, where f∈L~1(t_0,∞)∩C([t_0,∞,R]),P,Q,R∈C([t_0,∞,)R~+)and r,τ,σ∈(0, ∞). The sufficient conditions to oscillate for all solutions of this equation are studied.