Re: Sqrt problem - restated
- To: mathgroup@smc.vnet.net
- Subject: [mg12176] Re: Sqrt problem - restated
- From: Paul Abbott <paul@physics.uwa.edu.au>
- Date: Fri, 1 May 1998 03:08:28 -0400
- Organization: University of Western Australia
- References: <6i0usa$8pv@smc.vnet.net>
PAUL REISER wrote: > The problem I am having is something like how > do I get "2" out of this: > > Sqrt[a - b] Sqrt[a + b] > 1 + ----------------------- > 2 2 > Sqrt[a - b ] > > I'm starting to understand why Mathematica doesn't deal with this > because of the multiple value of square root, but if I know everything > under the square roots are positive, can I reduce this to 2 somehow > without substitution? (substitution would be prohibitively tedious in > my case) If substitution is prohibitively tedious you can add a rule like the following $Post = PowerExpand[# /. (a_)^(b_) :> Factor[a]^b]& which will do the simplification automatically. Cheers, Paul ____________________________________________________________________ Paul Abbott Phone: +61-8-9380-2734 Department of Physics Fax: +61-8-9380-1014 The University of Western Australia Nedlands WA 6907 mailto:paul@physics.uwa.edu.au AUSTRALIA http://www.pd.uwa.edu.au/~paul God IS a weakly left-handed dice player ____________________________________________________________________