c © TÜB_ITAK Oscillation Criteria for Second Order Nonlinear Dierential Equations with Damping

Oscillation criteria are given for second order nonlinear dierential equations with damping of the form (a(t) (x) _x)_+ p(t) _x + q(t)f(x) = 0; t t0; where p and q are allowed to change signs on [t0;1). We employ the averaging technique to obtain sucient conditions for oscillation of solutions of the above equation. Our results generalize and extend some known oscillation criteria in the literature