Thursday, May 17, 2012

What's a derivative?

I'm finishing up grading some of the limit/derivative quizzes I gave my precalc kids last week.  The last question said this:
What's a derivative?  (Where does it come from and what is it used for?)

(aka my way of seeing if they're paying attention in class or just using a formula)

This girl's answer:
A derivative is a simplified form of an equation that can be derived from the original and can be used to find the answers for different equations.

Um, no.

She had a lot more issues than this... every single one of her difference quotient expressions had x -> 0.

This girl also cried after my first semester exam. Apparently she didn't learn a lot from that experience.

No comments: