So an inflection point, an inflection point is a point where the sign of the second derivative, sign of second derivative, changes. Changes, so if you take the second derivative at that point, or as we go close to that point, or as we cross that point, it goes from positive to negative or negative to positive. And to think about that visually, you can think of some examples. So if you have a curve that looks something like this, if you have a curve that looks something like this, you'll notice that over here the slope is negative, but it's increasing. It's getting less negative, less negative, then it goes to zero, then it keeps increasing. Slope is increasing, increasing, all the way to there, and then it starts getting less positive. So it starts decreasing.