So what are going to be their corresponding y-coordinates on the curve? Well, this is the curve of y is equal to f of x. So this point right here is going to be f of our particular x right here. And maybe to show you that I'm taking a particular x, maybe I'll do a little 0 here. This is x naught. This is x naught plus h. This is f of x naught. And then what is this going to be up here?