Re: solve equation and domains
- To: mathgroup at smc.vnet.net
- Subject: [mg42159] Re: solve equation and domains
- From: Paul Abbott <paul at physics.uwa.edu.au>
- Date: Sat, 21 Jun 2003 02:49:36 -0400 (EDT)
- Organization: The University of Western Australia
- References: <bcrr8o$hnb$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <bcrr8o$hnb$1 at smc.vnet.net>,
"anto" <mendietanospam at virgilio.it> wrote:
> I must solve this equation x^3+(s+b+1)*x^2+(r+s)*b*x+2*b*s*(r-1)=0
> I wish the solutions in the domain r>1.
How about
<< Experimental`
CylindricalAlgebraicDecomposition[{
x^3 + (b + s + 1) x^2 + b (r + s) x + 2 (r - 1) b s == 0, r > 1},
{x, r, b, s}]
or, if you a Premier service customer and have already downloaded
version 5, use CylindricalDecomposition instead.
> If i can it's ,possible to solve in the domain r>b?
CylindricalAlgebraicDecomposition[{
x^3 + (b + s + 1) x^2 + b (r + s) x + 2 (r - 1) b s == 0, r > b},
{x, r, b, s}]
Cheers,
Paul
--
Paul Abbott Phone: +61 8 9380 2734
School of Physics, M013 Fax: +61 8 9380 1014
The University of Western Australia (CRICOS Provider No 00126G)
35 Stirling Highway
Crawley WA 6009 mailto:paul at physics.uwa.edu.au
AUSTRALIA http://physics.uwa.edu.au/~paul