Three y squared minus x. Once again, I'll say it the third time. Derivative of this times this plus the derivative of this times that. Alright, that's going to be equal to, on the right hand side, derivative of y with respect to x is just dy dx. Now if I want to, I could solve for the second derivative of y with respect to x, but what could be even better than that is if I substitute everything else with numbers, because then it's just going to be a nice, easy numerical equation to solve. So we know that we want to figure out our second derivative when y is equal to one. So y is equal to one, so that's going to be equal to one.