1. The problem statement, all variables and given/known data Find y''(x) of the parametric equation 9x^2+y^2=9 using implicit differentiation. 2. Relevant equations I already came up with y'(x) = -9x/y 3. The attempt at a solution Here is what I have for y''(x) so far y''(x) = d/dx (-9xy^-1) =-9(d/dx)(xy^-1) =-9(x(d/dx)(y^-1)+(y^-1)(dx/dx)) =-9(-x(y^-2)y'(x)+y^-1) I substituted the value of y'(x) = -9x/y here =-9((-x/(y^2))(-9x/y)+(1/y)) =-9((9x^2)/(y^3)+(1/y)) =(-81x^2)/(y^3)-(9/y) I know this is incorrect, I originally tried this using the quotient rule but was getting the same answer and the work was much more jumbled, so I opted for the product rule. The book states the answer is -81/(y^3). I am stuck and haven't been able to work towards the right answer.