- To: mathgroup at smc.vnet.net
- Subject: [mg32657] Re: Simplify
- From: "David P. Johnson" <johnson at nmtx.edu>
- Date: Sat, 2 Feb 2002 01:19:32 -0500 (EST)
- Organization: New Mexico Tech
- References: <email@example.com>
- Sender: owner-wri-mathgroup at wolfram.com
In article <a3f0q2$b3p$1 at smc.vnet.net>, Stich Sebastian
<seb_stich at gmx.ch> wrote:
> How can I simplify the following term?
> (a^(1/3) - b^(1/3)) * ((a^(2/3) + (ab)^(1/3) + b^(2/3))/(a-b))^(1/3)
> If I use the commands "Simplify", "FullSimplify", "Expand" or "PowerExpand"
> mathematica doesn't find the solution.
> The solution is (a^(1/3)-b^(1/3))^(2/3)
> If it's possible to find the solution in mathematica could mathematica show
> me the way this solution?
> Thanks for your answers!
Well, you could learn some algebra.
The quantity (a^(1/3)-b^(1/3)) does not equal (a-b)^(1/3), so you can't
cancel them. And didn't you mean ((a^(2/3) - 2(a*b)^(1/3) + b^(2/3))?
Even if you did, you can't change that to ((a^2 - 2(a*b) + b^2)^(1/3),
so you can't factor the expression inside the second parentheses. Your
proposed simplification is complete garbage. No wonder Simplify
didn't come up with it.
(Signature continues here)
N.B.: Remove the 'x' to email me
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