Re: Assumptions in Integrate
- To: mathgroup at smc.vnet.net
- Subject: [mg20579] Re: [mg20562] Assumptions in Integrate
- From: Andrzej Kozlowski <andrzej at tuins.ac.jp>
- Date: Sat, 30 Oct 1999 14:54:54 -0400
- Sender: owner-wri-mathgroup at wolfram.com
I also think the Assumptions mechanism in Integrate leaves a lot to be desired. Probably the best thing one can do right now is something like: In[45]:= Simplify[Integrate[Cos[n x], {x, -Pi, Pi}, Assumptions -> Element[n, Integers]], Element[n, Integers]] Out[45]= 0 -- > From: Julian Aguirre Estibalez <mtpagesj at lg.ehu.es> > Organization: Universidad del Pais Vasco/Euskal Herriko Unibertsitatea > Date: Sat, 30 Oct 1999 00:14:09 -0400 > To: mathgroup at smc.vnet.net > Subject: [mg20579] [mg20562] Assumptions in Integrate > > Dear Math Group, > > I find the results of using assumptions in Integrate somewhat > stranege. For instance, > > In[21]:= Integrate[Cos[n x], {x, -Pi, Pi}] > > Out[21]= 2 Sin[n Pi] > ----------- > n > > In[22]:= Integrate[Cos[n x], {x, -Pi, Pi}, > Assumptions -> Element[n, Integers]] > > Out[22]= > 2 > 2 Sin[Sqrt[n ] Pi] > ------------------ > 2 > Sqrt[n ] > > In[23]:= $Version > > Out[23]= "4.0 for Power Macintosh (July 20, 1999)" > > I know I can define my own transformation rules, but one would > think that Mathematica should do it directly. > > Julian Aguirre | Voice: +34 946012659 > Departamento de Matematicas | Fax: +34 944648500 > Universidad del Pais Vasco | Postal: Aptdo. 644, 48080 Bilbao, Spain > | email: mtpagesj at lg.ehu.es > >