And then at 2 thirds, we become concave upwards. Now let's see what happens when x is right less than, when x is just barely less than 0. So once again, f prime, the second derivative of x is equal to 12x times 3x minus 2. Well, right if x was minus point 1 or minus point 001, no matter what, this thing is going to be negative. This expression right here is going to be negative. The 12x, right, you have some negative value here times 12, it's going to be negative. And then what's this going to be?