## A word to avoid in math texts

I’d like to call a moratorium on this word.

Recall

as in

Recall the formula for the sum of a finite geometric sequence $a_1, a_1r, a_1r^2, a_1r^3, \dots , a_1r^{n-1}$ where $r \neq 1$ is $a_1 \cdot \frac{1-r^n}{1-r}$

Unless what you’re asking the reader to recall is in the same book as you’re writing, don’t use this word. Any prerequisite texts / courses your reader may have had might have used different terminology, or the class just skipped that section, or maybe they forgot so completely that there’s nothing to recall. Or perhaps they remember a particular formula exists, but based on the wording of “recall” feel silly that they hadn’t memorized it.