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Homework Help: Convert triangle vertices to double integral polar coordiantes

  1. Apr 19, 2010 #1
    1. The problem statement, all variables and given/known data

    integrate

    f(x,y) = sqrt(x^2+y^2)

    over triangle with vertices (0,0) (0,sqrt2) (sqrt 2, sqrt 2)

    2. Relevant equations

    x= rcosO, y = rsinO

    x^2+y^2=r^2
    3. The attempt at a solution

    im supposed to use a double integral converted to polar coordinates,
    so i used the bounds int. 0 to pi/4 int. 0 to sqrt 2 sec (r^2) drdO

    are these the correct bounds? because i cant seem to find the answer.
     
  2. jcsd
  3. Apr 19, 2010 #2
    I think your bounds for theta should be pi/4 to pi/2
     
  4. Apr 19, 2010 #3
    how do you know what the bounds are?
     
  5. Apr 19, 2010 #4
    because the line y=x cuts it at a 45 degree angle and x=0 goes up to 90 so it goes from 45 to 90
    like cutting a wedge out of a circle , but the radius is different , i think your bounds for the radius are correct.
     
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