It's really just to do it, it's better to do it from first principles where you find the volume of each of these disks and think of it that way. But let's just generalize what we saw in the last video. So instead of saying that this is y is equal to x squared, let's say that this is the graph, this function right over here, this function right over here, let's just generalize it and call it y is equal to f of x. And instead of saying we're going between 0 and 2, let's just say we're going between a and b. So these are just two endpoints along the x-axis. So how would we find the volume of this? Well, just like the last video, we would still take a disk just like this, but what is the height of the disk now?