Re: Integration variables

*To*: mathgroup at smc.vnet.net*Subject*: [mg78348] Re: Integration variables*From*: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>*Date*: Thu, 28 Jun 2007 06:35:34 -0400 (EDT)*Organization*: Uni Leipzig*References*: <f5vr6e$j12$1@smc.vnet.net>*Reply-to*: kuska at informatik.uni-leipzig.de

Hi, you have to write out d Cos[th] as -Sin[th] d th Regards Jens mattew wrote: > 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. >