Re: Log Error
- To: mathgroup at smc.vnet.net
- Subject: [mg78864] Re: Log Error
- From: Helen Read <hpr at together.net>
- Date: Wed, 11 Jul 2007 06:16:43 -0400 (EDT)
- References: <f6vnds$qfr$1@smc.vnet.net>
- Reply-to: HPR <read at math.uvm.edu>
Laurence Kohn 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?
You are indeed missing something. Log[x] is the natural log of x (base
e, not base 10). You might want to look up Log in the Help browser.
--
Helen Read
University of Vermont