Derive or differentiate? When the action is: Taking the derivative
what verb should be used?


*

*to differentiate

*to derive
I feel that deriving is not the correct word here. In my mind it's more a synonym of deducing. Am I right or has the word derive got the same meaning as differentiate? Or perhaps differentiate is not a proper English word...? If so, can anyone name a book or article  where the writer(s) (preferably native English speaker(s)) use the word derive to mean differentiate? Or should we always stick to saying: "Take the derivative of..."?
Edit: So from what I can tell, the phrase:  "Derive a method for differentiating this function and write down the resulting derivative.", can only have one meaning. XD
 A: That is a question for a native speaker, I fear.
In German both are used


*

*to differentiate = differenzieren (determing the derivative)

*to derive = ableiten -> Ableitung (derivative)


In English literature, I think I only saw differentiate for the operation. 
In German you can use "Herleitung" to stress more that it is about taking conclusions. In English it is maybe "derivation".
A: In English, I've almost always heard mathematicians say "We now differentiate $f$ to get ...". Occasionally I've heard "derive," but in English (my native language!), that's generally used to mean "work out", as in "Ralph couldn't derive a proof of the intermediate value theorem from the information he had at hand." It's also used in generating one thing from others, as in "We can now derive the half-angle formulas from the addition formula by a clever substitution." 
A: In mathematical/Calculus sense only: to differentiate is the verb "to find or calculate the derivative"
The noun is "the derivative"
Non-calculus students assume that it's ok to say or ask "how do I derive this function?" NO! Calculus students ask, "How do I differentiate this function?" Or "How may I find the derivative of this function?"
Conclusion: right now, in the 21st century Calculus instructors use the verb = differentiate and the noun = derivative 
