Oscillation and Nonoscillation Theorems for a Class of Fourth Order Quasilinear Difference Equations

In this paper, we consider certain quasilinear difference equations$$(A)~~~~~~~~~~~~~~~Delta^{2}(midDelta^{2}y_{n}mid^{alpha-1}Delta^{2}y_{n})+q_{n}midy_{ au(n)}mid^{eta-1}y_{ au(n)}=0$$where (a) $alpha,eta $ are positive constants; (b) ${q_{n}}_{n_{0}}^{infty}$ arepositive real sequences. $n_{0}in N_{0}={1,2,cdots }$.Oscillation and nonoscillation theorems of the above equation is obtained.