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!

To NoMoreExams

  1. Aug 14, 2008 #1
    On my post titled double integrals you explained why limits go from x^2 to x when integrating wrt y (i.e. the "bottom" graph is the bottom limit) however i seem to have found a webpage that disagrees with you http://www.libraryofmath.com/double-integral-over-a-more-general-region.html example (d) has limits in opposite direction you stated.
  2. jcsd
  3. Aug 14, 2008 #2
    It doesn't disagree, you just have to consider 2 different regions there since y = x - 1 isn't always below y^2 = 2x + 6. In fact on the interval [-3, -1], y = x - 1 doesn't even come to play. On that interval, the "lower" branch of your "parabola" (y = -sqrt(2x + 6)) is the lower bound and the "upper" branch (y = sqrt(2x + 6)) is the upper bound. However when you go to the interval [-1, 5], y = x - 1 is is the lower limit and the "upper" branch of y^2 = 2x + 6 is the upper bound.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?