Re: (-8)^(1/3)
- To: mathgroup at smc.vnet.net
- Subject: [mg31309] Re: (-8)^(1/3)
- From: Kevin McCann <Kevin.McCann at jhuapl.edu>
- Date: Sat, 27 Oct 2001 01:08:20 -0400 (EDT)
- Organization: Johns Hopkins University Applied Physics Lab, Laurel, MD, USA
- References: <9rb6rm$5ch$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
This works.
Kevin
ans = N[x /. Solve[x^3 == -8, x]]
{-2., 1. + 1.73205*I, 1. - 1.73205*I}
Select[ans, Conjugate[#1] == #1 & ]
{-2.}
"LuisMa" <nospam at newsranger.com> wrote in message
news:9rb6rm$5ch$1 at smc.vnet.net...
> When I enter
>
> (-8)^(1/3)
>
> Mathematica answer
>
> 1 + 1.73205i,
>
> but I need
>
> (-8)^(1/3) = -2
>
> How can I get it?
>
>