Class Of Unstable Neutral Difference Equations Bounded Vibration

This paper consist of three chapters. We respectively discuss the bounded oscillation of the following neutral difference equations with unstable type:In chapter 1, we investigated bounded oscillation for equation (I). The sufficient conditions obtained in chapter 1 improve the results in related literature. In chapter 2, we generalized the results of chapter 1 to equation (II). In chapter 3, the existence of unbounded positive solution of (III) is proved. Sufficient condtions for bounded oscillation and existence of bounded positive solution are obtained.