Dear LyX developers,
Both, "equation" and "formula" may refer to inline or displayed maths:
* text — text formulas are displayed inline, that is, within the body
of text where it is declared, for example, I can say that a + a = 2a
within this sentence.
* displayed — displayed formulas are separate from the main text.
---https://en.wikibooks.org/wiki/LaTeX/Mathematics
The term "formula" is consistently used for "displayed math" in LyX
(Math Guide, menus, and internally (inset Formula)).
However:
a) "Equation" is the usual term to refer to a "displayed formula":
1 + 1 = 2 (2)
As you can see in Equation 2, ...
b) The term "formula" has many connotations in English. Imagine you go
through the streets asking people what "formula" means. They might
think of "infant formula" (Babymilchpulver) or the Formula 1 circus.
Therefore "equation" (abgesetzte Gleichung) may be a better choice for
"displayed math".
Günter
