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Topic: Terrible algebraic system
Replies: 18   Last Post: Mar 8, 2012 4:26 AM

 Messages: [ Previous | Next ]
 Richard Fateman Posts: 1,539 Registered: 12/7/04
Re: Terrible algebraic system
Posted: Feb 22, 2012 10:05 AM

On 2/22/2012 6:10 AM, deltaquattro@gmail.com wrote:
> Hi,
>
> couldn't solve this with Wolfram Alpha, Matlab or Maxima:
>
> (a-L)^2/a*2/(a+b)-p=0
> (b-U)^2/b*2/(a+b)-p=0
>
> with a>L>0, b>U>0. Any tips? Should I resort to numerical methods?
>
> Best Regards
>
> Sergio Rossi

Mathematica seems to be perfectly happy to produce the symbolic answer,
which is many pages long (like, 80+) . It starts..
a -> 1/p((L p)/(2 - 3 p + p^2) - (L p^2)/(2 - 3 p + p^2) + (L p^3)/(
4 (2 - 3 p + p^2)) - 4 U + (4 U)/(2 - 3 p + p^2) - (6 p U)/(
2 - 3 p + p^2) + (5 p^2 U)/(2 (2 - 3 p + p^2)) - (p^3 U)/(
4 (2 - 3 p +
p^2)) - \[Sqrt]((-2 L p + L p^2 - 8 U + 8 p U - p^2 U)^2/(
4 (2 - 3 p + p^2)^2) - (
L^2 p^2 + 8 L p U + 24 U^2 - 16 p U^2 + p^2 U^2)/(
3 (2 - 3 p + p^2)) .....

Since the answer to this question is probably not useful to you, maybe
you should change the question. RJF