# Proving Euler Lagrange equations

1. Nov 24, 2015

### Frank Einstein

Hi everybody; I am looking for the deduction of the euler lagrange equations (d/dt)(∂L/∂v)-(∂L/∂x) from the invariance of the action δ∫Ldt=0.
Can someone please tell me where can I find It?

2. Nov 24, 2015

### julian

Last edited: Nov 24, 2015
3. Nov 24, 2015

### Frank Einstein

Thanks for the anwser; I was trying to prove this for a covariant lagrangian; the only differencie I spot with your proof is that I have to write √(1-(u/c)^2)dτ instead of dt.