So it has to move up to cross the x-axis there and over here. So what is the derivative doing at each of these critical points? Well, over here, our derivative is crossing from being positive. We have a positive derivative to being a negative derivative. So we're crossing from being a positive derivative to being a negative derivative. That was our criteria for a critical point to be a maximum point. Over here, we're crossing from a negative derivative to a positive derivative, which is our criteria for a critical point for the function to have a minimum value at a critical point.