Integrate over the region between the circles and .
So the integration itself is fine using the quotient rule, but how do I use the circles to get the limits of integration?
This problem works great in polar coordinates, but I think you made a typo because as written the numerator and denominator are the same.
EDIT: I see you already noticed this.
Ok, so in polar coordinates and the area of . So now you need to express the region in terms of polar coordinates, which should be easy since is a circle with radius a.