Question

why does ln1 equal 0?

Answer 1

Logarithms are powers of the base of the logs. If we consider logs to base 10, we find:$log_{10} 1=0$
This is because
$10^{0}=1$
Similarly for natural logs, where the base is the exponential number e, we have
$e^{0}=1$
This ensures that we have no problems with expressions such as the following:
$ln\ (\frac{60}{1})=ln\ 60-ln\ 1=ln\ 60-0=ln\ 60$