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Re: Real numerical computations

• To: mathgroup at smc.vnet.net
• Subject: [mg71773] Re: [mg71701] Real numerical computations
• From: Bob Hanlon <hanlonr at cox.net>
• Date: Tue, 28 Nov 2006 06:04:28 -0500 (EST)
• Reply-to: hanlonr at cox.net

x/.ToRules[Reduce[x^3==-1,x,Reals]]

-1

Needs["Miscellaneous`RealOnly`"];

(-1)^(1/3)

-1


Bob Hanlon

---- "José Carlos Santos" <jcsantos at fc.up.pt> wrote: 
> Hi all,
> 
> With Mathematica, if I type
> 
> N[(-1.)^(1/3)]
> 
> I get
> 
> 0.5 + 0.866025 i
> 
> This is correct, of course, but I would like to get -1. instead. How do
> I tell Mathematica that I want a real result (if there is one)?
> 
> Best regards,
> 
> Jose Carlos Santos
>