It is true that a critical point is x equals zero, but it is not the only critical point. So I would put that there. And the reason why it's important, you know, you might say, well, what's the harm in not noticing these other critical points? She identified one, maybe this is the relative maximum point. But as we talk about in other videos, in order to use the first derivative test, so to speak, and find this place where the first derivative is zero, in order to test whether it is a maximum or a minimum point is you have to sample values on either side of it to make sure that you have a change in sign of the derivative. But you have to make sure that when you test on either side that you're not going beyond another critical point because critical points are places where you can change direction. And so let's see what she does in step three right over here.