Title: Lagrangian vector field and Lagrangian formulation of partial differential equations
Author: M.Chen (Vanier College, 821 Ste-Croix Avenue, St. Laurent, Québec, Canada H4L 3X9)

In this paper we consider the Lagrangian formulation of a system of second order quasilinear partial differential equations. Specifically we construct a Lagrangian vector field such that the flows of the vector field satisfy the original system of partial differential equations.

Key words: Euler-Lagrange equations, vector fields, quasi-linear partial differential equations
PACS: 45.20.Jj, 02.30.Jr