TITLE: The origin/use of "derivative" and "differentiate"
QUESTION [14 upvotes]: Apologies if there is a duplicate somewhere; I couldn't find one.
The use of the root "deriv" in the context of differentiation seems odd: we have differentiation, differentials, differentiable, differential equations, and then for some odd reason, "derivative." Why/how did this happen?

REPLY [5 votes]: In French there is less of a problem with terminology: differentiation is called "dérivation", and derivative is, you guessed it, "la dérivée".  The term "fonction dérivée" was originally introduced by Lagrange.  The English term "differentiate" ultimately derives from "differences"; namely, Leibniz originally studied finite differences and discovered certain patterns that led him to introduce (infinitesimal) differentials.