The Math Forum

Ask Dr. Math - Questions and Answers from our Archives
Associated Topics || Dr. Math Home || Search Dr. Math

Deriving the Quotient Rule

Date: 9/5/95 at 17:11:23
From: Anonymous
Subject: math question

I'm a Swedish student at Chalmers and my math problem is:
how do I prove this derivation?

             (f/g)' = gf'-fg'/ g^2

Date: 9/6/95 at 12:23:14
From: Doctor Ken
Subject: Re: math question


You know, I don't think this is a dumb question at all!  This stuff can be
really tough and scary the first time you see it.

I think the easiest way to do this derivation is to write f/g as f*g^(-1).
Then you can use the product rule and the power rule to get the answer.  In 
fact, since the quotient rule (what you're trying to derive) is kind of hard
to remember, I usually end up re-deriving this every time I want to use it
or teach it to someone.

Good luck!

- Doctor Ken,  The Geometry Forum

Associated Topics:
High School Calculus

Search the Dr. Math Library:

Find items containing (put spaces between keywords):
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

Submit your own question to Dr. Math

[Privacy Policy] [Terms of Use]

Math Forum Home || Math Library || Quick Reference || Math Forum Search

Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.