Re: Problems with simplify and Sqrt[a^2]

*To*: mathgroup at smc.vnet.net*Subject*: [mg73896] Re: [mg73845] Problems with simplify and Sqrt[a^2]*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sat, 3 Mar 2007 00:48:59 -0500 (EST)*Reply-to*: hanlonr at cox.net

Sqrt[(-3)^2] 3 expr=v3/Sqrt[v1^2]/Sqrt[v2^2]-v3/v1/v2; Simplify[expr,{v1>0,v2>0}] 0 Bob Hanlon ---- dshortho <david.shorthouse at credit-suisse.com> wrote: > any help on this one: > > if you type in: > v3/Sqrt[v1^2]/Sqrt[v2^2] - v3/v1/v2 > > you get the same expression > > Even if you then type > Simplify[%] > > you still get the same expression > > I would have thought Mathematica would have resolved Sqrt[v1^2] to v1 (!?) > > Does anyone out there know why it does not do this, as it is causing some problems with some proofs I am doing ? >