# Irrational Number

An irrational number is real number that cannot be expressed as a ratio of two integers. When an irrational number is written with a decimal point, the numbers after the decimal point continue infinitely with no repeatable pattern.

The number "pi" or π (3.14159...) is a common example of an irrational number since it has an infinite number of digits after the decimal point. Many square roots are also irrational since they cannot be reduced to fractions. For example, the √2 is close to 1.414, but the exact value is indeterminate since the digits after the decimal point continue infinitely: 1.414213562373095... This value cannot be expressed as a fraction, so the square root of 2 is irrational.

As of 2018, π has been calculated to 22 trillion digits and no pattern has been found.

If a number can be expressed as a ratio of two integers, it is rational. Below are some examples of irrational and rational numbers.

• 2 - rational
• √2 - irrational
• 3.14 - rational
• π - irrational
• √3 - irrational
• √4 - rational
• 7/8 - rational
• 1.333 (repeating) - rational
• 1.567 (repeating) - rational
• 1.567183906 (not repeating) - irrational

NOTE: When irrational numbers are encountered by a computer program, they must be estimated.

Which of the following is not part of the authentication process for passkeys?

A
0%
B
0%
C
Public and private cryptographic keys
0%
D
A biometric scan or PIN
0%
Correct! Incorrect!     View the Passkey definition.
More Quizzes →

## The Tech Terms Computer Dictionary

The definition of Irrational Number on this page is an original definition written by the TechTerms.com team. If you would like to reference this page or cite this definition, please use the green citation links above.

The goal of TechTerms.com is to explain computer terminology in a way that is easy to understand. We strive for simplicity and accuracy with every definition we publish. If you have feedback about this definition or would like to suggest a new technical term, please contact us.