Re: (-8)^(1/3)
- To: mathgroup at smc.vnet.net
- Subject: [mg31319] Re: (-8)^(1/3)
- From: "Angel E. Andreu" <aandreu at localnet.com>
- Date: Sat, 27 Oct 2001 01:08:37 -0400 (EDT)
- References: <9rb6rm$5ch$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Using Mathematica v.4:
When I enter (-8)^(1/3) I received:
2(-1)^(1/3)
Given that you wrote your Mathematica response as 1 + 1.73205i,
reminds one of solving the cubic equation: x³ + 8 = 0. Thus, here are
some commands that yield your desired result of -2:
In[1]:= Solve[x³ +8 = = 0] [[1]]
Out[1] {x -> -2}
or
In[2]:= Root[ #1^3 + 8&, 1]
Out[2] -2
A²
LuisMa wrote:
> When I enter
>
> (-8)^(1/3)
>
> Mathematica answer
>
> 1 + 1.73205i,
>
> but I need
>
> (-8)^(1/3) = -2
>
> How can I get it?
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