square root of 2

The square root of 2MathworldPlanetmath is an irrational number, the first to have been proved irrational. Its decimal expansion begins 1.41421356237309504880168872420969807856… (sequence http://www.research.att.com/ njas/sequences/A002193A002194 in Sloane’s OEIS) Its simple continued fractionMathworldPlanetmath is


periodically repeating the 2. Some call this number Pythagoras’ constant.

There are several different ways to express 2 as an infinite product. One way is


another is



  • 1 Flannery, David. The square root of 2 : a dialogue concerning a number and a sequence. New York: Copernicus, 2006.
Title square root of 2
Canonical name SquareRootOf2
Date of creation 2013-03-22 17:29:12
Last modified on 2013-03-22 17:29:12
Owner MathNerd (17818)
Last modified by MathNerd (17818)
Numerical id 10
Author MathNerd (17818)
Entry type Definition
Classification msc 11A25
Synonym Pythagoras’ constant
Related topic Surd