RE: Re: Big problem in solving radicals.
- To: mathgroup at smc.vnet.net
- Subject: [mg41822] RE: [mg41786] Re: Big problem in solving radicals.
- From: "John C. Erb, Ph.D." <John_C_Erb at prodigy.net>
- Date: Fri, 6 Jun 2003 09:50:53 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hello, Would the package Needs["Miscellaneous`RealOnly`"] help you? See the Help Browser for RealOnly. John C. Erb email: John_C_Erb at prodigy.net -----Original Message----- From: Davide Del Vento [mailto:davide at astromeccanica.it] To: mathgroup at smc.vnet.net Subject: [mg41822] [mg41786] Re: Big problem in solving radicals. Hi. > {{x -> a^2}} > > *is* the general solution, nobody say that x (or a) > must be real. If a>0 this is not a solution of my equation, that is: + sqrt(x) + a == 0 And *NOT* - sqrt(x) + a == 0 > There is no way to ask Mathematica for only a real > solution in symbolic expressions. I don't want this, I would like to have something like this: x=a^2 if a<0 NONE if a>0 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