Given the surface z=x2−y2z = x^2 - y^2z=x2−y2, what is the gradient of the surface function at (1,1)(1, 1)(1,1)?
⟨2,−2⟩\langle 2, -2 \rangle⟨2,−2⟩
⟨1,−1⟩\langle 1, -1 \rangle⟨1,−1⟩
⟨2,2⟩\langle 2, 2 \rangle⟨2,2⟩
⟨−2,2⟩\langle -2, 2 \rangle⟨−2,2⟩