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### Product and Rules, How to Remember Them

```
Date: 10/19/95 at 10:6:7
From: Michal Wozniak
Subject: HELP

Hello.

I am sorry for disturbing you, but I need help. I forgot the formula for
the integral of f(x)*g(x) and f(x)/g(x). I can check in the handbook,
but I haven't any now.

Michal
```

```
Date: 11/3/95 at 15:24:46
From: Doctor Ken
Subject: Re: HELP

Hello!

I'll tell you the answer to your first question, and then show you a
song for the second.

The product rule says that the derivative with respect to x of f(x)*g(x)
is f'(x)*g(x) + f(x)*g'(x).

Here's the song that gives you the quotient rule.  It's to be sung to
the tune of "if you're happy and you know it clap your hands."

It's the bottom times derivative of the top (clap clap)
minus the top times the derivative of the bottom (clap clap)
and you put it all together over the bottom squared,
and there you have the quo-tient rule.

Ethan Magness wrote that one.  He's a fellow math doctor here.

-Doctor Ken,  The Geometry Forum

```
Associated Topics:
High School Calculus

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