Logarithm
From ACT Wiki
1.
The mathematical function which is the inverse of "raising to the power of".
Usually abbreviated to "log".
For example working with logarithms to the base 10:
log10(100) = 2
And 102 = 100
More generally with logarithms to the base n:
logn(x) = the power which, when 'n' is raised to it = x
For example 10(log10(x)) = x
And, more generally, n(logn(x)) = x
2.
The logarithm to the base 10.