When the logarithmic function is given by:
f (x) = logb(x)
The derivative of the logarithmic function is given by:
f ' (x) = 1 / ( x ln(b) )
x is the function argument.
b is the logarithm base.
ln b is the natural logarithm of b.
For example when:
f (x) = log2(x)
f ' (x) = 1 / ( x ln(2) )
