Critical points are where the derivative, they're points in the domain, so they're gonna have to satisfy x is greater than zero, such that g prime is either undefined or it is equal to zero. So let's first think about when g prime is equal to zero. So let's set it equal to zero. Two x natural log of x plus x is equal to zero. Well we can subtract, we could subtract x from both sides of that. And so we get two x natural log of x is equal to negative x. See, if we divide both sides by x, and we can do that, we know x isn't gonna be zero, our domain is x is greater than zero.