And it might be neither a minimum or a maximum point. But using the second derivative test, if we take the second derivative, and if we see that the second derivative is indeed less than zero, then we have a relative maximum point. So this is a situation that we started with right up there. If our second derivative is greater than zero, then we are in this situation right here, we're concave upwards. Where the slope is zero, that's the bottom of the bowl, we have a relative minimum point. And if our second derivative is zero, it's inconclusive. We don't know what is actually going on at that point, so we can't make any strong statement.