Re: Log Error
- To: mathgroup at smc.vnet.net
- Subject: [mg78834] Re: Log Error
- From: Norbert Marxer <marxer at mec.li>
- Date: Wed, 11 Jul 2007 06:00:45 -0400 (EDT)
- References: <f6vnds$qfr$1@smc.vnet.net>
On 10 Jul., 12:35, Laurence Kohn <L_K... at Nesbittgraphics.com> wrote:
> Hi,
>
> I had a question about something I found in Mathematica 5.2... I was
> plotting Log[x-1]-2 with x = {0,10} and y = {-10,5} and strangely found
> that the graph crossed the x-axes at approximately x == 8 ...
>
> It should be 101 of course, but it seemed like 8. Then I did an Nsolve
> with the equation set to 0, and low and behold got an answer x == 8.38906.
>
> Is this a bug in mathematica or am I missing something here?
Hello
Pleasem note that Log[x] is the logarithm with the base E (i.e.
2.71828...).
If you want the logarithm with the base 10 (as your question
indicates) you have to use Log[10,x].
Best Regards
Norbert Marxer