Well, what I very roughly just sketched out looks an awful lot like the brown graph right over here. So this brown graph does indeed look like the derivative of this blue graph. So what I would say is that this is actually f, and then this would be f prime, and then if this is f prime, the derivative of that is going to be f prime prime. So that looks good. I would actually go with this. And if you wanted, just for safe measure, you could try to sketch out what the derivative of this graph would be. Actually, let's just do that.