Re: Getting rid of ProductLog
- To: mathgroup at smc.vnet.net
- Subject: [mg49248] Re: Getting rid of ProductLog
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Fri, 9 Jul 2004 02:26:19 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <ccisbq$4de$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
if you are a programmer you may
a) implement a root search that solve the equation numerical
b) implement the ProductLog[] function
Regards
Jens
Robert Hulme wrote:
>
> Hi,
>
> Could someone please help me?
>
> I'm not a mathematician, but rather a programmer - I'm trying to use
> Mathematica to rearrange a formula for me.
>
> I'm trying:
>
> Solve[a^b - b == c, b]
>
> Which gives me:
>
> Out[3]//TextForm=
> Log[a]
> ProductLog[-(------)]
> c
> a
> {{b -> -c - ---------------------}}
> Log[a]
>
> The problem with this is that I need the solution to use normal
> 'primitive' (if thats the right word) math functions as I need the
> formula for a computer program.
>
> With ProductLog being an internal Mathematica function I cant
> therefore use this rearrangement.
>
> What can I do so that there is no ProductLog in there? Please go easy
> on me as I'm not a math major :0) or that au fait with Mathematica.
>
> If it helps both a and b are always positive.
>
> Many thanks
> -Rob