Problem 1294 (difficulty: 7/10)
We know that \(\displaystyle f:\R^2\to\R\) is differentiable and
\(\displaystyle y^2\cdot D_1f(x,y) + x^3\cdot D_2f(x,y) = 0. \)
Prove that \(\displaystyle f(\sqrt2,\sqrt[3]3)=f(0,0)\).