Re: a simplification problem

*To*: mathgroup at smc.vnet.net*Subject*: [mg55234] Re: [mg55172] a simplification problem*From*: DrBob <drbob at bigfoot.com>*Date*: Thu, 17 Mar 2005 03:29:20 -0500 (EST)*References*: <200503161035.FAA23728@smc.vnet.net>*Reply-to*: drbob at bigfoot.com*Sender*: owner-wri-mathgroup at wolfram.com

That's not a simplification; it's the wrong answer. Here's the right one (based on the commonly used "branch" of the exponential): ComplexExpand[(-1)^(1/3)] 1/2 + (I*Sqrt[3])/2 If you mean, "How do I extract the real third root of -1?", here's a method: ComplexExpand[x /. Solve[x^3 == -1]] {-1, 1/2 + (I*Sqrt[3])/2, 1/2 - (I*Sqrt[3])/2} First@Select[%, FreeQ[#1, Complex] & ] -1 Bobby On Wed, 16 Mar 2005 05:35:49 -0500 (EST), Hui Fang <fangh73 at xmu.edu.cn> wrote: > Dear All, > > My questions is simple: > How do I simplify (-1)^(1/3) to -1? > > Thanks! > > > > -- DrBob at bigfoot.com

**References**:**a simplification problem***From:*Hui Fang <fangh73@xmu.edu.cn>