How To Cancel A Natural Log

In mathematics, the logarithm of any number is an exponent to which another number, called a base, must be raised to produce that number. For example, since 5 raised to the third power is 125, the logarithm of 125 to the base 5 is 3. The natural logarithm of a number is a specific case in which the base is the irrational number e, equal to about 2.7183.

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Terminology and Notation

When using e as a base, you write "ln x," with the e subscript implied. This convention is similar to "log x," where base 10 is implied. This is because e and 10 are by far the most common bases found in everyday science and math applications.

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Canceling the Natural Log

Two important properties of logarithms make solving problems involving e simpler. These are: e raised to the power of (ln x) = x, and the ln of (e raised to the power of x) = x. For example, to find z in the expression

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12 = e to the power of 5z,

take the natural log of both sides to get

ln 12 = ln e to the power of 5z, or

ln 12 = 5z, which reduces to

z = (ln 12)/5, or 0.497.

Cite This Article

MLA

Crystal, Mike. "How To Cancel A Natural Log" sciencing.com, https://www.sciencing.com/cancel-natural-log-8205306/. 24 April 2017.

APA

Crystal, Mike. (2017, April 24). How To Cancel A Natural Log. sciencing.com. Retrieved from https://www.sciencing.com/cancel-natural-log-8205306/

Chicago

Crystal, Mike. How To Cancel A Natural Log last modified March 24, 2022. https://www.sciencing.com/cancel-natural-log-8205306/

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