Somaia Awad Al-Oufi2022-05-192022-05-191133https://drepo.sdl.edu.sa/handle/20.500.14154/10535One of the most important inequalities is opial inequality for functions of one variable which is important for studying the existence and uniqueness bounder less and stability of the solution of the ordinary differential equation. In this thesis we construct opial inequality for functions of n-independent viable. We discuss different forms of opial inequality functions of n-independent variables. All results of optial Yang and Salem opial inequality are considered as special caress of our work.enThesis