So in this case, our capital F of x, our antiderivative, is x to the third over 3. And so we just have to evaluate that at 4 and at 1. And sometimes the notation we'll use is, we'll say that the antiderivative is x to the third over 3, and we're going to evaluate it, the one I always like to just write the numbers up here, at 4 and from that subtract it, evaluate it at 1. Sometimes you'll see people write a little line here too, where they'll say we're going to evaluate it at 4 and then at 1, but I'll just do it without the line. So we're going to evaluate this thing at 4, and from that subtract it, evaluate it at 1. So this is going to be equal to 4 to the third power of 64, so it's going to be 64 over 3. Let me color code it.