Logarithm
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Logarithms or logs are a part of mathematics. A log is the inverse (opposite) of exponentiation; this is, it tells what exponent (power) is needed to make a certain number. So since
,
the logarithm to a base 2 of 8 is 3, written as:
Logarithms to base 10 are known as common logs and are usually written without the base; for example:
because 
because 10^(1.4082) = 25.6
Seeing that 10^1.41 = 25.704 and even 10^1.408 = 25.585, you might notice that it's important to keep at least four digits in the mantissa (the part of the number that follows the decimal on a logarithm) if precision is important.
[change] Common bases for logarithms
| base | abbreviation | Comments |
|---|---|---|
| 2 | lg | Very common in Computer Science |
| e | ln | The base of this is the Eulerian constant e, which is 2.718... |
| 10 | log | |
| any other number, n | logn | This is the general way to write logarithms |
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