1. Not finding help here? Sign up for a free 30min 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!

How do I calculate this double integral using a change of variables?

  1. Dec 13, 2013 #1
    The problem is as follows.

    Calculate the double integral of cos ((x-y)/(x+y)) dA over R, where R is the triangle bounded by the points (0,0), (2,2), and (2 + pi, 2 - pi).

    I understand that you have to set U = x-y and V = x+y. However, I am having a hard time finding the bounds on the integral because the slope of the lines isn't 1. I can't simply add x to the other side of each equation because of the 2+pi and 2-pi. Any help would be appreciated. Thanks!
     
  2. jcsd
  3. Dec 13, 2013 #2

    CAF123

    User Avatar
    Gold Member

    It is a case of mapping the coordinates of the points in Cartesians to uv space. When x=y=0, what are u and v? When x=y=2, what are u and v? Similarly, for x,y=2±π. Once you have pairs (u,v), you can sketch the resulting region and then determine the bounds for u and v.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: How do I calculate this double integral using a change of variables?
Loading...