Oscillation Theorems for Perturbed Second Order Nonlinear Differential Equations with Damping

摘要

Some oscillation criteria for solutions of a general perturbedsecond order ordinary differential equation with damping (r(t)x′ (t))′ + h(t)f (x)x′ (t) + ψ(t, x) = H(t, x(t), x′ (t))with alternating coefficients are given. The results obtained improve andextend some existing results in the literature.