Re: Weird result in Mathematica 6

*To*: mathgroup at smc.vnet.net*Subject*: [mg76431] Re: [mg76393] Weird result in Mathematica 6*From*: DrMajorBob <drmajorbob at bigfoot.com>*Date*: Tue, 22 May 2007 02:47:39 -0400 (EDT)*References*: <26727995.1179743868970.JavaMail.root@m35>*Reply-to*: drmajorbob at bigfoot.com

Even worse, FindRoot returns a wrong answer: g = Piecewise[{{0, x < 0}, {2 x - x^2, 0 <= x < 4}, {16 x - x^2, x³4}}]; h = x - 2; FindRoot[h == g, {x, 0}] {g, h} /. % {x->-2.84217*10^-15} {0, -2.} Bobby On Mon, 21 May 2007 05:01:21 -0500, Sebastian Meznaric <meznaric at gmail.com> wrote: > I was playing around with Mathematica 6 a bit and ran this command to > solve for the inverse of the Moebius transformation > > FullSimplify[ > Reduce[(z - a)/(1 - a\[Conjugate] z) == w && a a\[Conjugate] < 1 && > w w\[Conjugate] < 1, z]] > > This is what I got as a result: > -1 < w < 1 && -1 < a < 1 && z == (a + w)/(1 + w Conjugate[a]) > > Why is Mathematica assuming a and w are real? The Moebius > transformation is invertible in the unit disc regardless of whether a > and w are real or not. Any thoughts? > > > -- DrMajorBob at bigfoot.com

**Follow-Ups**:**Re: Re: Weird result in Mathematica 6***From:*Andrzej Kozlowski <akoz@mimuw.edu.pl>