Any number that is not rational. An irrational number cannot be written as the
of two integers.
See also Rational Number
An irrational number is simply the opposite of a rational number. (Recall that a rational number is one that can be represented as the ratio of two
See Rational number definition.)
Some common irrational numbers:
|e (Euler's number)
In all the above cases, the fraction will go on for ever with no discernible pattern. (Hence the ... after them).
None of the examples above can be accurately written as a fraction where both top and bottom are
In everyday use, the word 'irrational' usually means illogical, or not following reason. If someone is acting irrationally, they are doing strange things that seem illogical.
In mathematics, the word has a completely different meaning; it comes from the the word 'ratio'.
A rational number is one that can be written as the ratio of two integers. An irrational number is the opposite, one that cannot be written as a ratio of two integers.
An overview of the types of numbers that are used in math. Links to other pages explaining each type in depth. Explains also that some numbers are not numbers at all.
A rational number is one that can be represented as the ratio of two whole numbers.
While you are here..
... I have a small favor to ask. Over the years we have used advertising to support the site so it can remain free for everyone.
However, advertising revenue is falling and I have always hated the ads. So, would you go to Patreon and become a patron of the site?
When we reach the goal I will remove all advertising from the site.
It only takes a minute and any amount would be greatly appreciated.
Thank you for considering it! – John Page
Become a patron of the site at patreon.com/mathopenref
Other number topics
Numbers that have factors
(C) 2011 Copyright Math Open Reference. All rights reserved