A question on calculus of variations

[nenyan]

Homework Statement

δ (∂x'^μ/∂x^β)=0

This equation is on my textbook. I don't quite understand. Where x'^μ is coordinate component.

Homework Equations

The Attempt at a Solution

 

[vanhees71]

Is the transformation from $x$ to $x'$ given or what are your symbols supposed to mean?

 

[nenyan]

Yes. It's the transformation from $x$ to $x'$.
δ is Variational symbol.

Is the transformation from $x$ to $x'$ given or what are your symbols supposed to mean?

 

[vanhees71]

Ok, you must define the meaning of $x'$ or give the complete variational problem. I don't know, what's meant by this symbol!