How it is calculated
The number must be greater than zero. The base must also be greater than zero, and not 1.
log_b(a) = ln a / ln b
Where the numbers come from
- Kind
- Number
- Base
Example
The common logarithm of 1000 is 3, because 10³ = 1000.
Questions
Are lg and ln the same?
lg here is common, ln is natural, base e.
Logarithm of 1?
Equals zero for any allowed base.
A negative number?
Among the real numbers the logarithm is not defined, and the calculator stops.