Find the value of kkk such that the vector u=⟨1,k⟩\mathbf{u} = \langle 1, k \rangleu=⟨1,k⟩ is orthogonal to v=⟨2,−1⟩\mathbf{v} = \langle 2, -1 \ranglev=⟨2,−1⟩.
222
−2-2−2
111
000