But what's going to be going on, what's going on right here? At 2 thirds, we're exactly 0. But as you go, anything less than 2 thirds, 3 times 1 third is only 1. 1 minus 2, you're going to get negative numbers. So when x is less than 2 thirds, this thing right here is going to be negative. So the second derivative, if x is less than 2 thirds, the second derivative right to the left, or right when you go less than 2 thirds, the second derivative of x is less than 0. Now the fact that we have this transition from when we're less than 2 thirds, we have a negative second derivative, and when we're greater than 2 thirds, we have a positive second derivative, that tells us that this indeed is an inflection point.