Cube Root

Pronunciation: /kyub rut/ Explain

The cube root of an arbitrary value x is a value that, when multiplied by itself three times, equals x.[1] Stated mathematically, cube root of x equals a.

While a square root of a negative number is undefined for real numbers, the cube root of a negative number is possible. This is because a negative number multiplied by itself three times is still negative.

Examples of Cube Roots
cube root of 2 is about 1.25992105
Cube root of 5 is about 1.709975947
Cube root of 8 is 2
Table 1

Using a Calculator to Calculate a Cube Root

While some scientific calculators have a cube root button, most do not. To calculate the cube root of 3, type the following characters into your calculator, followed by the enter key: 3^(1/3). This works because the cube root of x is also x raised to the 1/3 power: Cube root of x is equal to x raised to the 1/3 power.


  1. cube root. Encyclopedia Britannica. Merriam-Webster. Last Accessed 8/6/2018. root.
  2. Oberg, Erik. Elementary Algebra. pg 8. Machinery's Reference Series. The Industrial Press. 1914. Last Accessed 8/6/2018. Buy the book
  3. Hines, G. D.. Mathematical roots uprooted, including square root, cube root, and other roots. pp 3-5. J. R. Holcomb & Co., Publishers. 1886. Last Accessed 8/6/2018. Buy the book

Cite this article as:

McAdams, David E. Cube Root. 6/25/2018. All Math Words Encyclopedia. Life is a Story Problem LLC.

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Revision History

6/25/2018: Removed broken links, updated license, implemented new markup, updated GeoGebra apps. (McAdams, David E.)
1/22/2010: Added "References". (McAdams, David E.)
11/25/2008: Changed equations to images. (McAdams, David E.)
7/11/2008: Changed equations to Hot_EQN. (McAdams, David E.)
1/5/2008: Initial version. (McAdams, David E.)

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