الفهرس 
ContentsOnly 14 pages are availabe for public view
 |  | from | 101 |  |  |
| | | from | 101 | | |
Abstract
The aim of this thesis is study the qualitative behavior of solution of some nonlinear difference equations of different orders. We discussed, in detail, the following Equilibrium points for difference equations; Local stability and global stability of the solutions of difference equations; Boundedness of solutions of difference equations; The periodicity of solutions of difference equations; This thesis consists of five chapter, and a list of references. Chapter (1) it is an introductory chapter and it deals with some basic definition and some result which will be useful in our study. In Chapter(2), we aim to study the periodic behavior of solutions of nonlinear difference equations. we use a new method to find the necessary and sufficient conditions for the existence of periodic solutions. Through examples, we compare the results of the new method with the results of the usual method. In Chapter(3), we study the qualitative behavior of a class of nonlinear difference equations by focusing on the periodicity, stability (local and global) and boundedness of its solutions. Furthermore, this equation involves a Mays Host parasitoid Model, as a special case. In Chapter(4), it is concerned with the asymptotic behavior of the solutions of a new class of nonlinear difference equations. We study the local and global stability of the solutions. Moreover, we investigate the new periodic character (periodic two and three) of the solutions of these equations. In Chapter(5), we are interested in studying a general class of nonlinear difference equations which includes two biological models as special cases. In detail, we study the qualitative behaviors (stability, boundedness and periodicity character) of solution of the studied equation. Our results generalize and complement some of the previous results in the literature. Moreover, some examples (with figures and tables) are considered to illustrate the main results.