Re: Simplify
- To: mathgroup at smc.vnet.net
- Subject: [mg32029] Re: [mg32007] Simplify
- From: BobHanlon at aol.com
- Date: Wed, 19 Dec 2001 04:29:10 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
In a message dated 12/18/01 2:59:34 AM, Matthias.Bode at oppenheim.de writes:
>why should I not expect MATHEMATICA to (Full)Simplify
>
>(a^b)^(1/b) or a^b^(1/b) to a?
Counter-example:
((-.7-.3I)^2.1)^(1/2.1)
0.7368942582104423 + 0.19231966154421648*I
(a^b)^(1/b) // PowerExpand
a
(a^(1/b))^b // PowerExpand
a
PowerExpand are correct in general only if c is an integer or a and b are
positive real numbers."
Simplify[(a^(1/b))^b, Element[{a,b}, Reals]&&a>0&&b>0]
a
Simplify[(a^b)^(1/b), Element[{a,b}, Reals]&&a>0&&b>0]
a
Simplify[(a^(1/b))^b, Element[b, Integers]]
a
Bob Hanlon
Chantilly, VA USA