Check out this youtube video about the epic battle between P and NP.

## P vs NP

## Four color game

http://www.kongregate.com/games/Onefifth/flood-fill

In this game the goal is to fill in the pieces with at most 4 colors. Two pieces that touch can’t share the same color. The game is mathematically interesting since the Four Color Theorem says that for any such ‘map’, four colors is enough.

## Shoe Lacing Math

**How many ways are there to tie your shoes?**

Depends on the shoes, but Ian has done some calculations (under certain assumptions) to show there are over 2 trillion ways!

Mathematician, Burkard Polster, published an article in the journal Nature (December 2002) about the mathematics of shoe lacing. His calculation for the number of ‘real-world’ lacing methods (of a shoe with 12 eyelets) is 43,200. He also has a shoe lace book that is published by the AMS.

## What is a mathematician?

Here are some quotes from famous people regarding mathematicians:

A mathematician is a device for turning coffee into theorems. (*Paul Erdős*)

A mathematician is a blind man in a dark room looking for a black cat which isn’t there. (*Charles Darwin*)

A person who can, within a year, solve x2 – 92y2 = 1 is a mathematician. (*Brahmagupta*)

Mathematicians, like cows in the dark, all look alike to me. (*Abraham Flexner*)

Mathematicians are like Frenchmen: whatever you say to them, they translate it into their own language, and forthwith it means something entirely different. (*Johann Wolfgang von Goethe*)

Medicine makes people ill, mathematics make them sad and theology makes them sinful. (*Martin Luther*)

## The most awkwardly named function in MATLAB

(via Reddit)

## Online Math Class…Fail…indeed

Thanks to Kei for this submission! And sorry you got the answer not correct…

He says:

“I did click “No” lol ( That is why there is no red “x” ) Sorry…but still nice work ahahh”

*If you have something funny related to math, then submit it to MathFail using our submission page and it might be posted. Cheers!

## Another crackpot “mathematician”

There’s lots of crackpots on the internet (and off the internet) who don’t understand some of the basics in mathematics. This person claims that:

“In 4,000 years of mathematics no one has been able to show a ratio for pi. We will show just how to produce that ratio. They state that pi is the ratio of the circumference of a circle to its diameter and then go on to prove that there is no ratio. Therefore concluding that the ratio is only a mere approximation of a true value. You will be surprised about how to establish a ratio for pi as well as how to prove that the present day calculation for pi is invalid.”

They later go on to prove that **pi = 201 / 64** by using “addition – subtraction – multiplication – division and square root extraction”.

Located at PureMathTheory.com.

## Bike with square wheels

I’m back to my regular update schedule. I was just visiting Macalester College and saw that they had the tricycle pictured below! I have seen pics on the internet of it but didn’t know where it existed.

The original was created in 1997 (and replaced in 2004) by Professor Wagon (not Professor Bike) and rolls smoothly over a road made out of inverted “catenaries”. See a video here for a demonstration.

## Making change

Consider the following hypothetical situation:

You are a cashier and you have to give the customer $0.40 in change, however, you have **no nickels** left in your till. The goal is to **minimize** the number of coins that the customer receives. How do you do it?

Well this actually happened, and the process the cashier went through was to:

- first take out a quarter (the highest denomination coin below $0.40),
- then take out a dime (the next highest denomination below $0.15),
- then finally, take out 5 pennies (since there is no nickels).

This produces 7 coins! The cashier realized this was not good, thought for a moment, then grabbed 4 dimes, which is the optimal solution in this case.

The “Change-making problem” is a well known problem you may have encountered if you have studied optimization. The problem is to see how one can give change with the least number of coins of given denominations.

The interesting thing is that for currency in North America, the **greedy algorithm** **always** produces an optimal solution (i.e. picking the largest denomination of coin which is not greater than the remaining amount). As we saw in the above example, if nickels were not allowable coins, the greedy algorithm would no longer produce an optimal solution for our currency denominations.

Check out the wikipedia links above for more info about this problem

## Recent Comments