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Re: Simplifying radicals

• To: mathgroup at smc.vnet.net
• Subject: [mg122224] Re: Simplifying radicals
• From: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>
• Date: Fri, 21 Oct 2011 06:24:48 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com

Hi, Tom,

There had been a package RealOnly in the past (i.e. before M6) for this purpose, and I am curious what replaces it now.

In between may be this:

rule=(-1)1/3(r)1;

(-729)^(1/3)/.rule

can help.

Best, Alexei

Hi,  I'm working with some introductory topics in radicals.

I know that Mathematica assumes things about the domain used in

problems,  so the principal cube root of a negative number will be

complex... or something like that..

I'm way down at the lower high school level simply working with cube

roots of negative numbers and wanting a negative number result.

I know there are ways of using assumptions and solving over the reals, etc.

Is there any EASY way I can simply ask for the cube root of -729 and get -9?

TOM

Alexei BOULBITCH, Dr., habil.

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