Question about notation

Jul 2008
5,248
58
Western Canada
I'm working on a derivation that will appear in a report. The derivation starts from a function that is a complicated formula involving integrals, multiplied by a simple term, like this:
$f(x) = 2\pi r [\;\text{complicated formula}\;]$
The simple $2\pi r$ term is carried through from beginning to end unchanged, and I'd like to omit it from the function definition to avoid unnecessary clutter in the derivation. Basically, I want to define a new function name that excludes the $2\pi r$ part. I could give it a totally different name, like $g(x)$, such that $f(x)=2\pi r \; g(x)$, but I'd rather keep the $f(x)$ function name and just add some character modifier such as a prime symbol, or something like that. Is there some kind of convention for this? Since the prime symbol usually denotes differentiation, I'm thinking that wouldn't be a good choice. Maybe a subscript?
 

romsek

Math Team
Sep 2015
2,969
1,676
USA
You're in the territory of do whatever you like as long as you define it clearly and use it consistently.
 
Jul 2008
5,248
58
Western Canada
Sounds good. I just don't want a black van with the math police showing up on my doorstep in the middle of the night.