So we're going to sum up the washers for each of our x's and take the limit as they approach 0. But we have to make sure we got our interval right. So what are these? We care about the entire region between the points where they intersect. So let's make sure we get our interval. So to figure out our interval, we just say, well, when does y equal x intersect y equal x squared minus 2x? So we just have to say, when does x, let me do this in a different color.