Where Formulas are Stored
Formulas are stored as Field Metadata as part of the Content-Type. If ever you need to do some manual operations (which you shouldn't need to do), you can find them here:
Tip
Normally you will just add/edit formulas in Interactive Formula Designer
As shown in this image, all fields having formulas are easy to discern:

You can create or edit Formulas them in the general field settings:

History
- Introduced in 2sxc 12.01
- Extended with
Required
ca. v13.00 - Extended with
Notes
ca. v13.10
Shortlink to here: https://go.2sxc.org/formulas