1. The problem statement, all variables and given/known data If the equations [tex]x^2 - 2(y^2)(s^2)t - 2st^2 = 1[/tex] [tex]x^2 + 2(y^2)(s^2)t + 5st^2 = 1[/tex] define s and t as functions of x and y, find [tex]\partial^2 t / \partial y^2[/tex] 3. The attempt at a solution Equating the two, we get 4y^2*s^2*t = -7s*t^2. My main problem is, as simple as this sounds, how do I implicitly differentiate a single term with three variables? (i.e. 4y^2*s^2*t) Because if I can implicitly differentiate it in terms of y, I can probably find [tex]\partial t / \partial y[/tex] in terms of the other partial derivatives.