XL: Formulas to Find the Log and Inverse Log of a Number

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Microsoft Excel has built-in functions to calculate the logarithm of anumber with a specified base, the logarithm with base 10, and the naturallogarithm. To calculate the inverse log of a number in the first twocases, raise the base to the power of the value returned by theparticular logarithm function being used. To find the inverse naturallog, use the EXP function.
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You can use the formulas in the following table to perform logarithmic and inverse log operations:
   Formula       Operation              Example            Result   ---------------------------------------------------------------------   =LOG(n,b)     Log base b of n        =LOG(8,2)          3   =(b)^(x)      Inverse log of the     =2^3               8                 number x, base b   =LOG10(n)     Log base 10 of n       =LOG10(100)        2   =10^(x)       Inverse log of the     =10^2              100                 number x, base 10   =LN(n)        Natural log of n       =LN(100)           4.6051702   =EXP(x)       Inverse natural        =EXP(4.6051702)    100                 log of the number x				
In the preceding table, n is a variable that is either a value or the address of a cell containing a value, b (in the first function) is the base with which the logarithm is calculated, and x is a variable representing the result of the log function being used.

NOTE: Unless a different value or cell address is specified, thedefault value for the base is 10.
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Article ID: 214116 - Last Review: 09/23/2015 06:46:00 - Revision: 6.0

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