[R] can R solve these paired equations

Robin Hankin r.hankin at noc.soton.ac.uk
Mon Dec 17 09:24:10 CET 2007


Hello

[An answer was posted just now using numerical ideas;
here is an answer from a symbolic perspective]

These equations involve x^y in more than one unknown,
so inverse functions cannot be used.

I do not think you will be able to characterize even the number
of solutions, let alone their nature.

To see the difficulty, look at the Lambert W function.

My advice would be to simplify, simplify, simplify
your problem as far as possible; remove terms
successively until you are left with a trivial
system, then add *one* term and see if
this produces any insights.

HTH

rksh



On 17 Dec 2007, at 05:43, Xin wrote:

> Dear:
>
>
>
> I have a paired equation below. Can I solve (x,y) using R.
>
>
>
> Thanks!
>
>
>
> Xin
>
>
>
> A=327.727
>
> B=9517.336
>
> p=0.114^10
>
>
>
> (1-p)*y*(1-x)/x/(1-x^y)=A
>
> A(1+(1-x)*(1+y)/x-A))=B
>
>
>
>
>
> 	[[alternative HTML version deleted]]
>
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--
Robin Hankin
Uncertainty Analyst and Neutral Theorist,
National Oceanography Centre, Southampton
European Way, Southampton SO14 3ZH, UK
  tel  023-8059-7743



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