Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2007
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2007

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Integration variables

  • To: mathgroup at smc.vnet.net
  • Subject: [mg78351] Re: Integration variables
  • From: dh <dh at metrohm.ch>
  • Date: Thu, 28 Jun 2007 06:37:11 -0400 (EDT)
  • References: <f5vr6e$j12$1@smc.vnet.net>


Hi mattew,

obviously Cos[Theta] is not a variable but a function. If you want to 

use it as a varible you must give it a valid name,e.g. costheta. But 

then you must write the integrand as a function of your variable, e.g.:

Integrate[ArcCos[costheta],{costheta,-1,1}]

hope this helps, Daniel



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.

> 




  • Prev by Date: Re: Why use Java in Mathematica?
  • Next by Date: Re: Integration variables
  • Previous by thread: Re: Integration variables
  • Next by thread: Re: Integration variables