And then the slope gets a negative. And then right over here, the slope is negative. So this is interesting because even though f is actually not differentiable right here, so f is not differentiable at that point right over there. And you can see because the slope goes pretty close to 0, then it just jumps to negative 3. So you have a discontinuity of the derivative right over there, but we do have a sign change. We go from having a positive slope on this part of the curve to having a negative slope over this part of the curve. So we experience a sign change right over here at x is equal to 0, a sign change in the first derivative of f, which is the same thing as saying a sign change in the second derivative of g. And a sign change in the second derivative of g tells us that when x is equal to 0, we have a point.