We have that the definite integral between a and b of v of t dt is equal to s of b minus s of a, where s of t is the anti-derivative of v of t. And this notion, although I've written in a very nontraditional used position velocity, this is the second fundamental theorem of calculus. And you're probably wondering about the first. We'll talk about that in another video. But this is a super useful way of evaluating definite integrals and finding the area under a curve. Second fundamental theorem of calculus, very closely tied to the first fundamental theorem, which we won't talk about now. So why is this such a big deal? Well, let me write it in a more general notation, the way that you might be used to seeing it in your calculus book.