Re: Re: Big problem in solving radicals.
- To: mathgroup at smc.vnet.net
- Subject: [mg41817] Re: [mg41786] Re: Big problem in solving radicals.
- From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
- Date: Fri, 6 Jun 2003 09:50:47 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Actually, I think that should have been: If[Re[a]<0||(Re[a]==0&&Im[a]<0),a^2,Solve[x^(1/2)+a==0] which, by the way, is the correct Mathematica syntax for this sort of thing. Andrzej Kozlowski Yokohama, Japan http://www.mimuw.edu.pl/~akoz/ http://platon.c.u-tokyo.ac.jp/andrzej/ On Thursday, June 5, 2003, at 10:38 pm, Andrzej Kozlowski wrote: > > On Thursday, June 5, 2003, at 08:31 pm, Davide Del Vento wrote: >> >> x=a^2 if a<0 >> NONE if a>0 > > > No, Solve or Resolve will never do that because they does not look for > real solutions. So what you mihgt get is: > > x==a^2 if Re[a]<0 > > I have heard a rumor that Resolve in the next version will do > something like that. But don't get your hopes too high, a pretty small > number of problems of this type can be resolved at all, though if you > can do it by hand presumably Mathematica will also be able to. > > Andrzej Kozlowski > Yokohama, Japan > http://www.mimuw.edu.pl/~akoz/ > http://platon.c.u-tokyo.ac.jp/andrzej/ > > >> In the case of this example things are pretty simple, but if you want >> I can give you a case in which this limitation is *very* big. >> >> Bye, >> ;Davide Del Vento >> >> CNR Istituto Fisica Spazio Interplanetario >> via del Fosso del Cavaliere, 100 / IT-00133 / Rome >> Phone: +390649934357 >> Fax: +390649934383 >> Mobile: +393288329015 >> E-Mail: davide @ astromeccanica.it >> E-Mail: del vento @ ifsi . rm . cnr . it >> >> >> > >