Assumptions in Integrate
- To: mathgroup at smc.vnet.net
- Subject: [mg20562] Assumptions in Integrate
- From: Julian Aguirre Estibalez <mtpagesj at lg.ehu.es>
- Date: Sat, 30 Oct 1999 00:14:09 -0400
- Organization: Universidad del Pais Vasco/Euskal Herriko Unibertsitatea
- Sender: owner-wri-mathgroup at wolfram.com
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