This is 1 4th. And this is 1 4th. And now we can solve for the second, can solve for the second derivative. Just going to make sure I don't make any careless mistakes. So it's six times one times 1 4th is going to be 1.5, or six times one times 1 4th is 6 4ths, minus one is going to be, so 6 4ths minus 4 4ths is 2 4ths. So this is going to be 1 half times 1 4th, times 1 4th, that's this over here, plus the second derivative of y with respect to x. And here I have one minus negative one.