Integration variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg78307] Integration variables*From*: mattew <m_manni_m at hotmail.com>*Date*: Thu, 28 Jun 2007 04:20:02 -0400 (EDT)

Hi everybody, Mathematica gives us the possibility to use spherical coordinates (r,Ttheta,Pphi): I'm trying to write an integral in the polar angle Ttheta of the form: Integral in [-1,1] Ttheta dCos(Ttheta) where Ttheta is the polar angle and the integration variable is the cosine of Ttheta in the interval [-1,1]. I got the following error: ntegrate::ivar: "Cos[Ttheta] is not a valid variable." Does anyone knows the reason for that? p.s: It happens with any system of coordinates, actually.