Re: Solve...or not
- To: mathgroup at smc.vnet.net
- Subject: [mg128546] Re: Solve...or not
- From: Bob Hanlon <hanlonr357 at gmail.com>
- Date: Fri, 2 Nov 2012 00:45:06 -0400 (EDT)
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- Delivered-to: l-mathgroup@wolfram.com
- Delivered-to: mathgroup-newout@smc.vnet.net
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- References: <20121101072008.AE953687B@smc.vnet.net>
$Version
"8.0 for Mac OS X x86 (64-bit) (October 5, 2011)"
eqns = {(y - 2)/(x - 1) == 1, y == 0};
Solve[eqns, {x, y}]
{{x -> -1, y -> 0}}
Solve[eqns, Variables[eqns]]
{{x -> -1, y -> 0}}
Simplify[Solve[eqns[[1]], x], eqns[[2]]]
{{x -> -1}}
Simplify[Solve[#[[1]], x], #[[2]]] &@eqns
{{x -> -1}}
Solve[eqns, x, Integers]
{{x -> ConditionalExpression[-1, y == 0]}}
Reduce[eqns, {x, y}] // ToRules
{x -> -1, y -> 0}
Reduce[eqns, x] // ToRules
{y -> 0, x -> -1}
Eliminate[eqns, y] // ToRules
{x -> -1}
Bob Hanlon
On Thu, Nov 1, 2012 at 3:20 AM, Harker, Anthony <a.harker at ucl.ac.uk> wrote:
>
> I've seen some discussion of Version 8's Solve[] in this group, but have I missed something explaining this?
>
> I have the following behaviour (both under Windows 7)
>
>
> Mathematica 8.0.1.0
>
> Solve[{(y-2)/(x-1)==1,y==0},x]
> {}
>
> Mathematica 7.0.1.0
> Solve[{(y-2)/(x-1)==1,y==0},x]
> {{x->-1}}
>
> Tony
>
> Tony Harker
> Department of Physics and Astronomy
> University College London
> Gower Street
> London
> WC1E 6BT
>
> Tel: (within UK) 020 7679 3404
> (overseas ) +44 20 7679 3404
> E: a.harker at ucl.ac.uk
>
> [...] clay possesses one considerable advantage: it is resistant to fire, water, and magnetic disturbances. In [...] a few thousand years, our photographs, books and hard disks will no doubt have disappeared, but our collections of cuneiform tablets will still be there.
>
> Dominique Charpin, Reading and Writing in Babylon (2010) translated by Jane Marie Todd.
- References:
- Solve...or not
- From: "Harker, Anthony" <a.harker@ucl.ac.uk>
- Solve...or not