A symmetry classification for a class of (2+1)-nonlinear wave equation

In this paper, a symmetry classification of a (2+1)-nonlinear wave equation utt−f(u)(uxx+uyy)=0utt−f(u)(uxx+uyy)=0 where f(u)f(u) is a smooth function on uu, using Lie group method, is given. The basic infinitesimal method for calculating symmetry groups is presented, and used to determine the general symmetry group of this (2+1)-nonlinear wave equation.