deletions | additions       diff --git a/untitled.tex b/untitled.tex  index 09e37dc..bb0b3ad 100644  --- a/untitled.tex  +++ b/untitled.tex 
...
L = - \left(1- \frac{2M}{r}\right) \dot{t}^2 + \left(1-\frac{2M}{r}\right)^{-1} \dot{r}^2 + r^2 (\dot{\theta}^2 + \sin{\theta}^2 \dot{\phi}^2)  $$  It does not depend explicitly on $t$ and $\phi$, so $\frac{dL}{d\dot{t}}$ and $\frac{dL}{d\dot{\phi}}$ will be the constants of motion: motion (from the Euler-Lagrange equations):  $$  -\frac12 \frac{dL}{d\dot{t}} = \left(1- \frac{2M}{r}\right) \dot{t} = \epsilon