Difference between revisions of "Pi"
m (→Definition) |
Mathgeek2006 (talk | contribs) (→Definition) |
||
| Line 1: | Line 1: | ||
== Definition == | == Definition == | ||
| − | '''Pi''' is an [[irrational]] number. It is the ratio of a circle's circumference, or perimeter, to its diameter. It is roughly equal to 3.141592653. The number pi is usually only useful when dealing with [[circle|circles]], [[sphere|spheres]], and discs. | + | '''Pi''' is an [[irrational]] number. It is the ratio of a circle's circumference, or perimeter, to its diameter. It is roughly equal to 3.141592653. The number pi is usually only useful when dealing with [[circle|circles]], [[sphere|spheres]], and discs. The fractional approximation for pi (not exact) can be <math>\frac{22}{7}</math>. The exact formula for pi is <math>4\left( \sum_{i = 0}^\infty (-1)^i \left(\frac{1}{2n+1}\right)\right) </math> |
== See Also == | == See Also == | ||
*[[Circle]] | *[[Circle]] | ||
Revision as of 19:46, 21 June 2006
Definition
Pi is an irrational number. It is the ratio of a circle's circumference, or perimeter, to its diameter. It is roughly equal to 3.141592653. The number pi is usually only useful when dealing with circles, spheres, and discs. The fractional approximation for pi (not exact) can be 
. The exact formula for pi is 
