So we have a general formula for no matter what my delta x is, I can find the slope between 3 and 3 plus delta x, between those two points. Now, we wanted to find the slope at exactly that point right there. So let's see what happens when delta x gets smaller and smaller. This is what delta x is right now. It's this distance. But if delta x got a little bit smaller, then it would start, the secant line would look like that. Got even smaller, the secant line would look like that.