The multiplication sign ✕ Posted on 2019/11/04 by Carl Reply The multiplication sign ✕ as now used universally was first introduced by the English mathematician and clergyman William Oughtred in 1631. pic.twitter.com/z0OIT76N5J— Fermat's Library (@fermatslibrary) November 2, 2019

GeoGebra’s New CAS Calculator App: limits, derivatives, integrals, etc Posted on 2019/11/04 by Carl Reply GeoGebra’s New CAS Calculator

Prime numbers and God Posted on 2019/11/01 by Carl Reply "God may not play dice with the universe, but something strange is going on with the prime numbers" – Paul Erdös (1997) pic.twitter.com/wzvN6QMk6o— Fermat's Library (@fermatslibrary) November 1, 2019

Viggo Brun and the flaw in the Intel Pentium Microprocessor Posted on 2019/10/31 by Carl Reply In 1919, Viggo Brun proved that the sum of the reciprocals of twin primes converges to Brun's constant. In 1994, Thomas Nicely discovered a flaw in the Intel Pentium Microprocessor while calculating Brun's constant. It cost Intel millions of dollars to replace the faulty chips! pic.twitter.com/tI9APBVtdn— Fermat's Library (@fermatslibrary) October 31, 2019

Pythagorean triple via hyperbolic reflections Posted on 2019/10/28 by Carl Reply Three integers satisfying a² + b² = c² form a Pythagorean triple, which can be drawn as a right triangle, or a point (a/c, b/c) on the unit circle. Amazing fact: starting with the four Pythagorean triples (±1,0,1), (0,±1,1) all others can be generated via hyperbolic reflections. pic.twitter.com/XORBHcbM1Z— Keenan Crane (@keenanisalive) October 25, 2019

Power sum MASTER CLASS: How to sum quadrillions of powers … by hand! (Euler-Maclaurin formula) Posted on 2019/10/26 by Carl Reply

Half and Half Posted on 2019/10/25 by Carl Reply Don't just skim over this comic! #FunFriday #DOMATH pic.twitter.com/TzauRhK2Eh— Center of Math (@centerofmath) October 25, 2019