Minus 12.5. And we want to figure out an x that minimizes this area. So this derivative right over here is defined for any x. So we're not going to get our critical point by figuring out where the derivative is undefined. But we might get a critical point by setting this derivative equal to 0 to figure out what x values make our derivative 0. When do we have a 0 slope for our original function? And then we just have to verify that this is going to be a minimum point.