Independent Variable

Pronunciation: /ˌɪn.dɪˈpɛn.dənt ˈvɛər.i.ə.bəl/ Explain

Figure 1: Graph of f(x) = x2

An independent variable is a variable whose value can vary (change) independently of other variables. Another way to state this is the value of the independent variable does not depend on the value of any other variable. In functions, an independent variable is also called an input variable. In figure 1, f(x) = x2, the independent variable is x. You can tell the input variable when using function notation because it is inside the parenthesis of the function declaration.

Cricket Population Year 1992 1994 1996 1998 Population 2053 1740 2741 2286 Figure 2: Table of cricket population by year.

The table in Figure 2 represents a function. The independent variable is Year. This is because the year exists independently of the cricket population, and the cricket population is dependent on the year.

References

1. McAdams, David E.. All Math Words Dictionary, independent variable. 2nd Classroom edition 20150108-4799968. pg 97. Life is a Story Problem LLC. January 8, 2015. Buy the book
2. independent variable. merriam-webster.com. Encyclopedia Britannica. Merriam-Webster. Last Accessed 8/7/2018. http://www.merriam-webster.com/dictionary/independent variable. Buy the book
3. Long, Edith and Breknke, W. C.. Algebra, First Course. pg 208. www.archive.org. The Century Co.. 1913. Last Accessed 8/7/2018. http://www.archive.org/stream/algebrafirstcour00longrich#page/208/mode/1up/search/independent. Buy the book
4. Bettinger, Alvin K. and Englund, John A.. Algebra and Trigonometry. pp 53-54. www.archive.org. International Textbook Company. January 1963. Last Accessed 8/7/2018. http://www.archive.org/stream/algebraandtrigon033520mbp#page/n70/mode/1up/search/independent. Buy the book

Cite this article as:

McAdams, David E. Independent Variable. 4/23/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/i/independentvariable.html.

Image Credits

• All images and manipulatives are by David McAdams unless otherwise stated. All images by David McAdams are Copyright © Life is a Story Problem LLC and are licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Revision History

4/23/2019: Updated equations and expressions to new format. (McAdams, David E.)
3/19/2019: Clarified wording. (McAdams, David E.)
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
8/6/2018: Removed broken links, updated license, implemented new markup, implemented new Geogebra protocol. (McAdams, David E.)
2/11/2010: Added "References". (McAdams, David E.)
8/9/2008: Added vocabulary link 'vary', clarified sentence on independent variable and function notation. (McAdams, David E.)
7/12/2007: Initial version. (McAdams, David E.)