Irrational Number

Updated About encyclopedia.com content Print Article Share Article
views updated

Irrational Number

An irrational number is a number that cannot be expressed as a fraction, that is, cannot be written as the quotient of two whole numbers. As a decimal, an irrational number is shown by an infinitely long nonrepeating sequence of numbers. Examples of commonly used irrational numbers are π (pi, the ratio of circumference to diameter of a circle); e, base of the natural logarithms); and 2 (that number which multiplied by itself equals 2). There is an infinite number of irrational numbers.

See also e (number); Rational number.