So let's see, what would make this undefined? Two x to the x, that you can evaluate for any x. Natural log of x, once again, is only going to be defined for x greater than zero. But that's, we've already restricted ourselves to that domain. So within the domain, any point in the domain, our derivative is actually going to be defined. So given that, let's see what's happening on either side of this critical point. On either side of this critical point.