Tag Archives: theorem

Four formats for Fermat

In my previous post I mentioned Fermat’s Little Theorem, a beautiful, fundamental result in number theory that underlies lots of things like public-key cryptography and primality testing. (It’s called “little” to distinguish it from his (in)famous Last Theorem.) There are … Continue reading

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New baby, and primality testing

I have neglected writing on this blog for a while, and here is why: Yes, there is a new small human in my house! So I won’t be writing here regularly for the near future, but do hope to still … Continue reading

Posted in meta, number theory, primes | Tagged , , , | 9 Comments

Apollonian gaskets and Descartes’ Theorem II

In a few previous posts I wrote about “kissing sets” of four mutually tangent circles, and the fact that their signed bends satisfy Descartes’ Theorem, (Remember that the signed bend of a circle is like the curvature , except that … Continue reading

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Apollonian gaskets and Descartes’ Theorem

In my previous post, I explained a recursive procedure for drawing Apollonian gaskets. Given any three mutually tangent circles, there are exactly two other circles which are mutually tangent to all three (forming what we called a “kissing set”). This … Continue reading

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Book review: Fermat’s Enigma

Fermat’s Enigma: The Epic Quest to Solve the World’s Greatest Mathematical ProblemSimon Singh After having it recommended to me several times, I finally picked up this book when I happened to see it at our favorite local used bookstore. I … Continue reading

Posted in books, open problems, proof, review | Tagged , , , | 10 Comments