Re: assumptions question
- To: mathgroup at smc.vnet.net
- Subject: [mg21934] Re: assumptions question
- From: "FRESSENGEAS Nicolas" <nicolas.fressengeas at supelec.fr>
- Date: Fri, 4 Feb 2000 02:55:01 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
I think there are still lots of bugs in the assumptions part of Simplify. Just tell Mathematica developers so they will include this in the next generation :-<> -- _____________________________________________ Dr. Nicolas Fressengeas Equipe de Recherche en Photonique et Opto=E9lectronique Sup=E9lec, 2 rue E.Belin, 57070 METZ Cedex Tel: 33 387 764 705 ... Fax: 33 387 764 700 http://www.ese-metz.fr/metz/personnel/fresseng/fresseng.html Plan d'acc=E8s: http://www.iti.fr/PlanPerso/affichplan.hei?codeunique==23704&noplan==1 When everything else fails, read the instructions... Peter Jay Salzman <psalzman at landau.ucdavis.edu> a =E9crit dans le message : 87b0rh$o6c at smc.vnet.net... > Dear all, > > I have an integral whose output contains things which look like: > > (Sign[m] - I Sign[h t]) > > Since m is mass, h is hbar and t > 0, I placed placed a: > > Assumptions -> {Sign[m] > 0, Sign[t h] > 0} > > inside the Integrate[ ] command. > > Integrate[ Sin[k r]/(k r) * Exp[-I*(h k)^2 t /(2 m h)], > Assumptions-> {Sign[m] > 0, Sign[t h] > 0}, > {k, 0, Infinity}] > > It seems to be ignoring me. The Sign[m]'s keep showing up. Is there a way > to tell Mathematica that m is always positive? I *thought* this was the way of > doing it... > > pete > >