Oscillation Theorems for Second Order Nonlinear Differential Equations with Forced Terms

In this paper, we investigate the oscillation of second order nonlinear differential equation of the form where . There exists a function r ∈ C²(I, R) such that e(t)= r″(t) and r changes sign on [T, ∞) for any T ≥ t₀, f ∈ C(I × R, R), f(t, y)sgny ≥ q(t)|y| or f(t, y)=q(t)f₁(y). By using the generalized Riccati technique and averaging technique, we get some new oscillation criteria for it.