MathGroup Archive 2007

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

Search the Archive

Re: Integration variables



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