So when x is equal to negative two, that is what the tangent line looks like, and you can see its slope. And then as we increase x, we can see that the slope is positive, but it is decreasing. Then it goes to zero, and then it goes negative, and the slope keeps decreasing all the way until we get, it looks like, we get to about x equals negative one, and then our slope begins to increase again. So something interesting happened right at x equals negative one. And so that's a pretty good indication. We're just doing it graphically here. We're not proving it.