Question

Find ∂f /∂x , ∂f /∂y , and ∂f /∂z . f(x, y, z) = 18/ (x² + y² + z²)

∂f/∂x=

∂f/∂y=

∂f/∂z=

Find their values at (0, −1, 1) if possible. (If an answer is undefined, enter UNDEFINED.)

∂f/∂x(0, −1, 1)=

∂f/∂y(0, −1, 1)=

∂f/∂z(0, −1, 1)=