So right over here, we actually have the graph of our function h. This is a graph y is equal to h of x. And we don't have graphed the first derivative, but we do have graphed the second derivative right here in this orange color, h prime prime. So they're telling us, given that h prime of negative four is equal to zero. So that's saying that given that the first derivative at x equals negative four is equal to zero, and you can see that the slope of the tangent line when x is equal to negative four does indeed equal zero. So given that, what is a calculus-based, let me underline that, a calculus-based justification for the fact that h has a relative maximum at x equals negative four? So this first one says that the second derivative at x equals negative four is negative. Now what does that tell us?