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: Double integral tough

  1. Jun 5, 2010 #1
    1. The problem statement, all variables and given/known data

    [itex] \int_{0}^{1} \int_{0}^{1} \sqrt{4x^2 + 4y^2 + 1} dx\,dy [/itex]

    3. The attempt at a solution

    This integral is tough for me, I couldn't think of a way to evaluate it. Can you suggest me the first step to do this problem?

    Thanks!
     
  2. jcsd
  3. Jun 5, 2010 #2

    CompuChip

    User Avatar
    Science Advisor
    Homework Helper

    The sum of squares strongly suggests a change to spherical coordinates (in 2D, that would be polar coordinates).

    An integral like
    [tex] \int r \sqrt{1 + r^2} \, dr [/tex]
    is easier, because r is the derivative of 1 + r2.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook