Quantcast
Channel: Math – David Richeson: Division by Zero
Browsing latest articles
Browse All 19 View Live

Image may be NSFW.
Clik here to view.

Bubble diagrams for functions in LaTeX using TikZ

I am teaching Discrete Math this semester (our intro-to-proof course). One of the topics is functions. Not surprisingly my students and I have to draw “bubble diagrams” for functions between finite...

View Article



Image may be NSFW.
Clik here to view.

2013: the year of pi

A couple days ago I saw this tweet. This is the year of pi. Arctan2 + Arctan1 + Arctan0 + Arctan3 = pi. #pi @centerofmath @MathJesus1 @CutTheKnotMath @maanow @mathematicsprof— John Molokach...

View Article

Image may be NSFW.
Clik here to view.

Gabriel’s paper horn

I just returned from the eleventh Gathering for Gardner. One of the many special things about this unusual conference is that the attendees are strongly encouraged to participate in the “gift...

View Article

Image may be NSFW.
Clik here to view.

Measuring Tapes for Circles and Spheres

I’d like to thank Matt Parker for introducing me to diameter tapes (or D-tapes). These are measuring tapes used by foresters to measure the diameters of trees. The forester wraps the measuring tape...

View Article

Image may be NSFW.
Clik here to view.

Two More Impossible Cylinders

Earlier this year I wrote a couple blog posts about reverse engineering Sugihara’s impossible cylinder illusion. I then wrote it up more formally, and it has appeared in Math Horizons (pdf). The...

View Article


Image may be NSFW.
Clik here to view.

Math Crafts: Salt Designs, Newton Snowflakes, Fractal Christmas Trees, Paper...

I have had a crafty late fall and early winter. I’ve been good about posting my crafts on Twitter, but not so good at blogging about them. So, I’ve collected them all and will share them all here in...

View Article

Image may be NSFW.
Clik here to view.

My First Crossword Puzzle

I recently discovered Phil, an HTML5 crossword puzzle maker (here it is on GitHub). I’ve always wanted to make a crossword puzzle, but it seemed overwhelming. But with Phil, I found it fun and...

View Article

Image may be NSFW.
Clik here to view.

BraidTiles—A Mathematical Braid Puzzle

We can view braids mathematically as n strings hanging from a horizontal bar.  Each piece of string runs downward and can cross neighboring strings. In the 1920s Emil Artin observed that braids of n...

View Article


Image may be NSFW.
Clik here to view.

The Magnificent Möbius Band

As I write this blog post, we are all either struggling with the impact of the COVID-19 virus or waiting nervously as cases start to rise in our area. I am currently teaching remotely. My college...

View Article


Image may be NSFW.
Clik here to view.

Make a Real Projective Plane (Boy’s Surface) out of Paper

I am teaching an undergraduate course in topology. We are now looking at what we get if we take a square and glue the sides together. (These are called identification spaces.) We are assuming that our...

View Article
Browsing latest articles
Browse All 19 View Live




Latest Images