# Variational calculus

#### PeteSampras

1. The problem statement, all variables and given/known data

Question:

If $r_+ \neq r_{++}$ and $g(r=r_+) \neq g(r=r_{++})$

When is it fulfilled that $d g (r=r_+) \neq d g (r=r_+)$ ?

2. Relevant equations
$r_+ \neq r_{++}$
$g(r=r_+) \neq g(r=r_{++})$

3. The attempt at a solution

I tried computing $dg(r_+) = \frac{\partial g}{\partial r} \Big |_{r=r_+} dr_+$, but i am very confused. This is all the information that i have of this problem.

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Gold Member
Can you define #r_{+} , r_{++}$for us? Do it through a forehand or backhand, either is OK ;). #### PeteSampras Can you define #r_{+} , r_{++}$ for us? Do it through a forehand or backhand, either is OK ;).
I dont understand your assumption. $r=r_+$ and $r=r_{++}$ are two differents points such that $r_{++}>r_+$

#### WWGD

Gold Member
I dont understand your assumption. $r=r_+$ and $r=r_{++}$ are two differents points such that $r_{++}>r_+$
Sorry, a tennis joke; guess you're tired of them ;).

"Variational calculus"

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