Re: ComplexityFunction affects set of transformations tried by Simplify

*To*: mathgroup at smc.vnet.net*Subject*: [mg71550] Re: ComplexityFunction affects set of transformations tried by Simplify*From*: "Schochet" <schochet at netvision.net.il>*Date*: Wed, 22 Nov 2006 05:22:30 -0500 (EST)*References*: <200611202311.SAA18396@smc.vnet.net><ejuqdp$htk$1@smc.vnet.net>

On Nov 21, 2:11 pm, Andrzej Kozlowski <a... at mimuw.edu.pl> wrote: > On 21 Nov 2006, at 08:11, Schochet wrote: > > > As part of a large computation, I wanted Mathematica to > > simplify expressions of the form Sqrt[c + d/k](c k + d)2, > > where k is positive, to (c k + d)^(5/2)/Sqrt[k] > > > Rather unlikely, I would say. Consider that my Mathematica 5.1 gives: > > expr1 = Sqrt[c + d/k]*(d + c*k)*2; > expr2 = (d + c*k)^(5/2)/Sqrt[k]; > > Simplify[expr1 == expr2, k > 0] > > (d + c*k - 2)*Sqrt[d + c*k] == 0 > > So, the way I see it there are two possibilities. One is, that there > was something funny with the state of your Mathematica when you got > those results. If not, then I am pleased that I have not upgraded > from version 5.1 to 5.2 ;-) > > Andrzej Kozlowski > Tokyo, Japan In the course of transferring expr1 from Mathematica to my mail program (on a different computer), the ^ before the final 2 got lost. So expr1 should be: expr1 = Sqrt[c + d/k]*(d + c*k)^2 Can you try the calculation again in Mathematica 5.1? I ran it in a new Mathematica 5.2 session, so I don't think the state of the sessuion is an issue. Steve

**References**:**ComplexityFunction affects set of transformations tried by Simplify***From:*"Schochet" <schochet@netvision.net.il>