symmetry group classification for general equation

The present paper solves the problem of the group classification of the general equation ut = λu2x + µuxt where λ and ξ are arbitrary smooth functions of thevariable x and u, by using lie method. the paper is one of the few application of analgebraic approach to the problem of group classification. the method of preliminarygroup classification. a number of new interesting nonlinear invariant models whichhave nontrivial invariance algebras are obtained the result of the work is a wide class ofequations summarized in table form.