And then you are going to get the volume of that figure. So the volume of that figure is going to be equal to, so the volume is going to be equal to the integral from x equals a all the way, so that's approximately, you know, approximate, well I'll just write a over here, to x equals 2 of this business. This is the length of one side of the square. But we want to square it, because that's going to give us the area of that cross section. And then, so let's do that. So times, I could say the absolute value of f of x minus g of x. I could just square that. Or if I want, I could just put parentheses there.