1. The problem statement, all variables and given/known data Find and classify the critical points of f(x,y,z) = xy + xz + yz + x^3 + y^3 + z^3 2. Relevant equations - 3. The attempt at a solution df/dx = y + z +3x^2, df/dy = x + z + 3y^2 and df/dz = x + y + 3z^2 a point x is a critacal point if the gradient equals 0. Obviously (0,0,0) is a critical point but I´m not sure how to find the others.