And so now we just have to evaluate this. So this is going to be equal to 1 3rd times, see, the antiderivative of x squared is x to the third over three. Antiderivative of one is x, and we're going to evaluate it from zero to three. And so this is going to be equal to 1 3rd times, when we evaluate it at three, let me use another color here, when we evaluate it at three, it's going to be three to the third divided by three. Well, that's just going to be 27 divided by three. That's nine plus three. And then when we evaluate it at zero, minus zero, minus zero.