So that's our first one right over there. Then this might be our second one. And let's do right Riemann sum, where the right boundary of our rectangle, what the value of the function is at that point, that's what defines the height. So that's our second one, all the way until this one right over here is going to be our nth one. So this is one, let me write it this way. This is i is equal to one, this is i is equal to two, all the way until we get to i is equal to n. And then if we take the limit as n approaches infinity, the sum of the areas of these rectangles are going to get better and better and better. And so let's first think about it.