Um Kalthoum Suliman Kanona2018-11-252018-11-252007-11http://hdl.handle.net/123456789/13629In 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 me/thods, variation methods and energy integral method. We have illustrated the techniques with some examples.enInverse problems (Differential equations)Differential equations, PartialPartial differential operators.Thesis