(Al Neelain University, 2004) Sami H i gazi Mustafa
In this research we utilize the symmetry condition of
differential equations to solve some of these equations .
Also we show how Lie algebra methods are much
advanced for understanding and unifying all classical
methods of solving differential equations . At the end of
our research we discuss the variational methods and
Euler — Lagrange equations on the light of symmetry
