Re: Integration variables
- To: mathgroup at smc.vnet.net
- Subject: [mg78431] Re: [mg78307] Integration variables
- From: DrMajorBob <drmajorbob at bigfoot.com>
- Date: Sun, 1 Jul 2007 07:47:22 -0400 (EDT)
- References: <10055979.1183020713484.JavaMail.root@m35>
- Reply-to: drmajorbob at bigfoot.com
You didn't post the code, so it's just a guess what you actually entered, but... Rather than Integrate[f[x], g[x]], you must use Integrate[f[x] g'[x], x]. Bobby On Thu, 28 Jun 2007 03:20:02 -0500, mattew <m_manni_m at hotmail.com> 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. > > -- DrMajorBob at bigfoot.com