Hello ..! I need to get me out of trouble, is that I missed a lot of classes and see the notes do not understand! I have an exercise that tells me: Evaluate the double integral INT (D) (x ^ 2-y ^ 2) where the region defined by
0 <= x <= 1 x ^ 2-y ^ 2> = 0.

Well, my question is how change of coordinates, and what are the limits of integration in these coordinates!
It may be that X = r * cos @ and y = r * sin @ where @ is the angle?
and the new integral I is:
INT (D) = (r * cos @) ^ 2 - (r * sin @) ^ 2 * r * dr * d @

If not well done the change of variable!, And the limits of integration would they?
0 <=@<= 2pi
r and I have no idea! xq x ^ 2-y ^ 2> = 0 and usually I have <= 1: (

well, I hope an explanation, I hope you understand something! haha, is a bit boring around here!
Greetings and thanks!