You could try to integrate with respect to X or you could integrate with respect to Y. I'm gonna argue it's much easier to integrate with respect to Y here because we already have things in terms of DY. The volume of this little slice is going to be Y times X times DY. Now if we wanna integrate with respect to Y, we want everything in terms of Y. And so what we need to do is express X in terms of Y. So here we just have to solve for X. So one way to do this is, let's see, we can square both sides of, well actually let's divide both sides by four. So you get Y over four is equal to the square root of nine minus X.