Change of Base Formula
Pronunciation: /tʃeɪndʒ ʌv beɪs ˈfɔɹ.mjə.lə/ Explain
The change of base formula is used to change the
The change of base formula is
When logarithms were first invented, there were no calculators. Mathematicians and
astronomers used books published with tables of logarithms. Each table had exactly one
base. To find a logarithm with another base, they used the change of base formula.
Today, most calculators and math based computer programs have logarithms in two
bases: base 10 and base e.
To find a logarithm in any other base, one must use the change of base formula.
|Figure 1: Change of base mnemonic.||
- Solve log24.
- Solve log522.
- McAdams, David E.. All Math Words Dictionary, change of base formula. 2nd Classroom edition 20150108-4799968. pg 32. Life is a Story Problem LLC. January 8, 2015. Buy the book
- Bettinger, Alvin K. and Englund, John A.. Algebra and Trigonometry. pg 113-114. www.archive.org. International Textbook Company. January 1963. Last Accessed 6/25/2018. http://www.archive.org/stream/algebraandtrigon033520mbp#page/n130/mode/1up/search/base. Buy the book
- McAdams, David E.. Logarithm. allmathwords.org. All Math Words Encyclopedia. Life is a Story Problem LLC. 6/27/2018. http://www.allmathwords.org/en/l/logarithm.html.
Cite this article as:
McAdams, David E. Change of Base Formula. 4/13/2019. All Math Words Encyclopedia. Life is a Story Problem LLC. http://www.allmathwords.org/en/c/changeofbaseformula.html.
12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
6/25/2018: Removed broken links, updated license, implemented new markup, updated GeoGebra apps. (McAdams, David E.)
1/11/2010: Added "References", "More Information". (McAdams, David E.)
11/25/2008: Initial version. (McAdams, David E.)