The symmetry group method is applied to a generalized Korteweg-de Vries
equation and several classes of group invarint solution for it are obtained by
means of this technique. Polynomial, trigonometric and elliptic function
solutions can be calculated. It is shown that this generalized equation can be
reduced to a first-order equation under a particular second-order differential
constraint which resembles a Schrodinger equation. For a particular instance in
which the constraint is satisfied, the generalized equation is reduced to a
quadrature. A condition which ensures that the reciprocal of a solution is also
a solution is given, and a first integral to this constraint is found