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Topic: Cannot get inverse of y=x/logx to work
Replies: 5   Last Post: May 30, 2011 2:03 PM

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William Elliot

Posts: 1,948
Registered: 5/30/08
Re: Cannot get inverse of y=x/logx to work
Posted: May 30, 2011 2:42 AM
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On Sun, 30 May 2011, Chris Richardson wrote:
> On Mon, 30 May 2011 15:16:32 +1000, Brad Cooper wrote:
>

>> I cannot get the correct result for the inverse calculation of y =
>> x/log(x).

>
> Equations of this type are solvable in terms of the
> Lambert function:
>
> x = -y * W(-1/y), where W is the Lambert function
>

W(y) is the solution to y = xe^x; W(y).e^W(y) = y.

You claim -yW(-1/y)/log(-yW(-1/y) = y.

How so?



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