Oscillatory and asymptotic properties of solutions of nonlinear fourth order difference equations

The authors consider the difference equation Δ2 (rn Δ2 yn) qn f(yn) = Qn; n = 1,2,3,... (*) where rn > 0, qn > 0, for all n 1 and f : is continuous such that uf(u) > 0 for u 0. Dividing the solutions of (*) into several classes for the cases Qn = 0 and Qn 0, the authors obtain conditions for the existence / nonexistence of solutions of (*) in these classes. Examples are inserted to illustrate the results