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Re: Getting rid of ProductLog


if you are a programmer you may
a) implement a root search that solve the equation numerical
b) implement the ProductLog[] function


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

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