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 the point (1,1,1)(1, 1, 1)(1,1,1) in the direction of v=⟨1,0,1⟩\mathbf{v} = \langle 1, 0, 1 \ranglev=⟨1,0,1⟩.
000
12\frac{1}{\sqrt{2}}21
2\sqrt{2}2
111