Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help with this double integral

  1. Jul 9, 2005 #1
    i would need help with this integral:

    [tex] \int_a^{\infty}\int_a^{\infty}dxdyF(y/x) [/tex]

    now i make the change of variable y/x=u x=v then what would be the new integration limits?..thanks.

    where a can be 0 or 1
    Last edited: Jul 9, 2005
  2. jcsd
  3. Jul 9, 2005 #2


    User Avatar
    Science Advisor
    Homework Helper

    U can't make that substitution. I hope you see why. Depending on the shape of the function "F", you may integrate directly. The integral may very easily diverge, but that wouldn't be a catastrophe, would it...?

  4. Jul 9, 2005 #3


    User Avatar
    Science Advisor

    You can make u the inner integral. The limits will be a/x to inf. and you will have 1/x in the integrand. v=x is irrelevant - it doesn't change anything.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Help with this double integral
  1. Double Integral Help (Replies: 1)