# Math Books

## Learning discrete math (with DUCKS)

What could be better than learning math with silly problems and situations!

Source:** Discrete Mathematics with Ducks** by *Sarah-Marie Belcastro*

http://books.google.ca/books?id=UYtlK8waqasC&lpg=PA73&pg=PA103#v=onepage

I’m definitely considering this book for when I start teaching Discrete Math!

## Math Books

Infinity is scary…

Dedication in textbook: To my grandson…

## Mathematics Patch Notes

(via Spiked Math)

**Patch Notes 1.02a**

“Mathematics will never be the same.”

Introducing Probability 2.0

- Upgraded probability to include real numbers in the range from 0 to 2.
- Switching in the monty hall problem is now the same as not switching.
- Due to high demand, correlation now implies causation.

Graph Theory Features

- Fixed glitch in the petersen graph so it is no longer a counter-example.
- Support is no longer offered for hypergraphs.
- Added a new color to the outdated 4-color theorem. We anticipate at least 7 colors available for planar graphs by patch 1.03.

**Number Systems**

- Decimal notation will be phased out next patch. This should fix the long standing bug that 1 = 0.999…
- Due to loneliness, the set of prime numbers now includes the number 1.
- Complex numbers have been deemed no longer complex and will now be known as “easy numbers”.

Proof Changes

- Proof by “reference to inaccessible literature” is no longer accessible.
- A new “proof by picture” widget has been added for mac users.

Miscellaneous

- Support has been added to allow division by 0 fixing the wormhole bug.

## Math books

I wouldn’t mind having this one.

## In the glossary of a programming textbook

(via Reddit)

This was posted by ooglag on Reddit who says it’s from John Zelle’s Python Programming, although it’s pretty common in other text books as well. It also reminds me of google:

http://www.google.ca/search?q=recursion

## Caution!

**This is in a textbook:**

CAUTION!

The area of a washer is

CAUTION!

The area of a washer is

*pi*R^2-pi*r^2*, which you can simplify to*pi*(R^2-r^2)*, but not to*pi*(R-r)^2*. No matter how tempting it is to make the latter simplification, it’s wrong. Don’t do it.