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 absolute value.

  1. Nov 27, 2011 #1
    1. The problem statement, all variables and given/known data

    I just need to know if what i did is correct. The question is as follows:



    2. Relevant equations

    3. The attempt at a solution

    What I did is as follows:

    I split this integral into two parts and solved.

    [integral from 0 to 1 [integral from x to -2x (e^(x+y)) dy] dx] +
    [integral from -1 to 0 [integral from -x to 2x (e^(x+y)) dy] dx]

    The way of thinking about it is that y goes from x to -2x when x goes from 0 to 1 and -x to 2x when x goes from -1 to 0.

    Is that right?
  2. jcsd
  3. Nov 27, 2011 #2


    User Avatar
    Science Advisor
    Homework Helper

    Yep, the idea is good, just check which boundary is the upper and which is the lower one.
    For example, if 0 < x < 1, then -2|x| = -2x < 0 and |x| = x > 0.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook