In this case, it's square root of x. So it's going to be pi times our radius squared, which is pi times square root of x squared. And so if we want to find the volume of the entire outer thimble or truffle or whatever we want to call it, before we even carve out the center, we just take a sum of a bunch of these disks that we've created. So that's one disk. We would have another disk over here, another disk over here. For each x, we have another disk. And as we go, as x's get larger and larger, the disks have a larger and larger radius.