Solution of "borderline" eqs. in Mathematica, Maple, and Maxima (was "linsolve")
Subject: Solution of "borderline" eqs. in Mathematica, Maple, and Maxima (was "linsolve")
From: Andrej Vodopivec
Date: Tue, 3 Apr 2007 18:08:13 +0200
On 4/3/07, Richard Fateman <fateman at cs.berkeley.edu> wrote:
> You have not specified the complete meaning of the solution. Here are some
> issues, I think.
I just ran the examples given by Kostas and noted that some results
produced by Solver are closer to what he wanted than the results
produced by solve.
> Solving 1=1 for x should be "any value of x". Is that what you mean by
> []???
Well "any value of x" would be incorrect also since the original
equation was x/x=1. I would say that the answer [] is wrong.
> Solving a*x=x is either x=0 or a=1. What does Solving ([a*x=x],[x,a])
> do?
Solver([a*x=x], [x,a]) => [[x=0]]. I would say that this is wrong too.
> Also, the question is y-3 positive, negative, or zero? .... What if y-3
> is complex?
> Maybe you mean zero or non-zero?
This comes from a call to asksign. When the original program was
ported from commercial Macsyma to Maxima, asksign was used to replace
askcsign which does not exist in Maxima. I guess that askcsign would
also check if y-3 is complex in commercial Macsyma.
--
Andrej