Re: [Axiom-math] Simple question

[Soren Hansen]

On Mon, Dec 04, 2006 at 09:55:01PM +0100, Ralf Hemmecke wrote:
> >The problem I actually wanted to solve was:
> >solve((250/x)^x-6000000000,1.e-5)
 
> Sorry to say, but that is not a good problem description.

I suppose I could have been more precise. I just expected the context to
make up for my lack of detail. I wanted to solve (250/x)^x=6000000000 to
to a precision of 10^-5. In my other example I managed to do that by
giving solve an expression for which it found the values of x where the
expression evaluated to zero. I - naïvely - thought a similar approach
would be sensible.

> Try to formulate the problem without the "solve" function and specify
> clearly what solutions you accept. For example, there is no solution
> to
> 
> (250/x)^x = 6000000000
> 
> if you require x to be a natural number.

I was looking for an approximation with a set precision.

> You probably don't want that, but your problem description is too
> vague. If you leave the computer to guess something for you then you
> should prepare that a possible "answer" is not that what you expect.

> PS: Maple 9.5 says
> 
> fsolve((250/x)^x-6000000000);
> 226.3269985
> 
> If that is of any help.

Thanks, but I actually already found the answer using Maple. Maple's
version of solve gave me two solutions, each using LambertW.  One
evaluated to ~226 and the other ~6. 

I am merely trying to get the hang of Axiom in order to ditch Maple and
this seemed like a simple starting point.

-- 
Cheers, Søren Hansen.

signature.asc
Description: Digital signature