Consider the function f(x,y,z)=x2+y2+z2f(x, y, z) = x^2 + y^2 + z^2f(x,y,z)=x2+y2+z2. What is the divergence of its gradient, ∇⋅(∇f)\nabla \cdot (\nabla f)∇⋅(∇f)?
666
2x+2y+2z2x + 2y + 2z2x+2y+2z
333
000