1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Integral over a surface

  1. Aug 2, 2010 #1
    I am having problem with an integral. I dont know how to write in mathcode so excuse me for my notation.

    This is in spherical coordinates:

    x = theta
    y = psi
    r = radial component

    the integrand is: (cos(x)/r^2)

    I want to integrate this over a solid angle of an arbitrary surface.

    da is a differential area. And in spherical coordiantes should be: da = r^2*sin(x)dxdy

    I know the integral should be 4*pi but I dont get it right. I want to have the antiderivate as (cos(x)^2)/2 from 0 to pi.

    Then I get 1/2*2pi = pi

    So I am missing a factor 4 here. Can anyone help me show what I've missed?
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted