So g prime prime of x is just the derivative of the first derivative with respect to x, and so more of the power rule, three x squared minus 24 x to the first, or just 24 x, plus 48. So let's think about where this switches signs. And this is a continuous function, it's going to be defined for all x's, so the only potential candidates of where it could switch signs are when this thing equals zero. So let's see where it equals zero. So let's set it equal to zero. Three x squared minus 24 x plus 48 is equal to zero. Let's see, everything is divisible by three, so let's divide everything by three.