Um Kalthoum Suliman Kanona2018-09-272018-09-272007-11http://hdl.handle.net/123456789/12909A§STfiA€T" In this study, we considered existence and uniqueness problems for partial differential equations. . We used functional analysis techniques, where a partial differential equation is regarded as an operator on an appropriate Hilbert space. This Hilbert space is in fact a Sobolev space. In particular, we have dealt with two methods, variation methods and energy integral method. We have illustrated the techniques with some examples.enMathematicsThesis