a simple question about EulerEquations
- To: mathgroup at smc.vnet.net
- Subject: [mg96059] a simple question about EulerEquations
- From: kem <kemelmi at gmail.com>
- Date: Wed, 4 Feb 2009 05:17:29 -0500 (EST)
Hi,
It seems that mathematica gives a different expression for Euler-
Lagrange equation.
Isn't the answer to:
EulerEquations[ f[u'[x],u[x],x] , u[x] , x]
should be:
Derivative[0, 1, 0][f][Derivative[1][u][x], u[x], x] -
Derivative[1, 0, 1][f][Derivative[1][u][x], u[x], x] ==0
?
The output that I am getting from mathematica is:
Derivative[0, 1, 0][f][Derivative[1][u][x], u[x], x] -
Derivative[1, 0, 1][f][Derivative[1][u][x], u[x], x] -
Derivative[1][u][x]*
Derivative[1, 1, 0][f][Derivative[1][u][x], u[x], x] -
Derivative[2][u][x]*
Derivative[2, 0, 0][f][Derivative[1][u][x], u[x], x] == 0
Thank you