Originally Posted by
Plato I think his/her last posting is about change of base, and also some confusion about notation.
More and more, we see this being used: $\displaystyle \log (x)\text{ for }\ln (x)$.
Most computer algebra systems use that convention.
Nevertheless, historically $\displaystyle \log (x)\text{ meant }\log_{10} (x)$ hence confusion.
Using the newer notation we get the classic change of base formula.
$\displaystyle \log _{10} (b) = \frac{{\log (b)}}{{\log (10)}}$.
In this usage it is the case that $\displaystyle \log (10)\not=1$.