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Re: Log Error

  • To: mathgroup at smc.vnet.net
  • Subject: [mg78833] Re: [mg78805] Log Error
  • From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
  • Date: Wed, 11 Jul 2007 06:00:14 -0400 (EDT)
  • References: <200707101027.GAA26861@smc.vnet.net>

On 10 Jul 2007, at 19:27, 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?
>
>
>
>

Log in Mathematica means the natural logarithm (usually donoted by  
ln) and not the base 10 logarithm, and for the natural logarithm we  
have: Log[E^2+1-1]==Log[E^2] ==2. Hence the solution of your equation is
N[E^2 + 1]
8.38906

Andrzej Kozlowski


  • References:
    • Log Error
      • From: Laurence Kohn <L_Kohn@Nesbittgraphics.com>
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