I encourage you to pause the video and see if you can work through it on your own. So let's remind ourselves how a definite integral can relate to a Riemann sum. So if I have the definite integral from a to b of f of x, f of x dx, we have seen in other videos, this is going to be the limit as n approaches infinity of the sum, capital sigma, going from i equals one to n. And so we're essentially going to sum the areas of a bunch of rectangles, where the width of each of those rectangles, we can write as a delta x. So your width is going to be delta x of each of those rectangles. And then your height is going to be the value of the function evaluated someplace in that delta x. If we're doing a right Riemann sum, we would do the right end of that rectangle or of that subinterval. And so we would start at our lower bound, a, and we would add as many delta x's as our index specifies.