Re: Simplify
- 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: <a3f0q2$b3p$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
In article <a3f0q2$b3p$1 at smc.vnet.net>, Stich Sebastian <seb_stich at gmx.ch> wrote: > Hello > > 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. -- -David (Signature continues here) N.B.: Remove the 'x' to email me