Find the directional derivative of f(x,y,z)=x2+y2+z2f(x, y, z) = x^2 + y^2 + z^2f(x,y,z)=x2+y2+z2 at (1,0,0)(1, 0, 0)(1,0,0) in the direction ⟨1,1,1⟩\langle 1, 1, 1 \rangle⟨1,1,1⟩.
2/32/\sqrt{3}2/3
222
1/31/\sqrt{3}1/3
3\sqrt{3}3