Natural logarithm
The natural logarithm is the logarithm with base e. It is usually denoted , an abbreviation of the French logarithme normal, so that
However, in higher mathematics such as complex analysis, the base 10 logarithm is typically disposed with entirely, the symbol
is taken to mean the logarithm base e and the symbol
is not used at all. (This is an example of conflicting mathematical conventions.)
Calculus definition
In calculus, the natural logarithm is defined by .