Question 245060
<pre><font size = 4 color = "indigo"><b>
{{{ln(18)}}}

means the same as:

{{{log(e,(18))}}}

The change of base formuls is

{{{log(OLD_BASE,(X))}}}{{{"="}}}{{{log(NEW_BASE,(X))/log(NEW_BASE,(OLD_BASE))}}}

Here the OLD BASE is e and the NEW BASE in 10. so

{{{log(e,(18)) = log(10,18)/log(10,e)}}}

Instead of "log<sub>e</sub>" we write "ln" for the natural log.

and instead of "log<sub>10</sub>" we just write "log" for the

common log, so

{{{ln(18) = log((18))/log((e))}}}

Edwin</pre>