# Understanding Equation Form

1. ### strokebow

101
Hi,

Example:

Maxwell Relation (thermoD)...

($\frac{∂μ}{∂T}$)$_{p,n}$ = - ($\frac{∂S}{∂n}$)$_{T,p}$

what does it mean having those subscript variables outside of the brackets.

thanks

### Staff: Mentor

They are kept constant in the process. For example, the left side is the change of µ if you change T, but keep p and n constant.