Which vectors are orthonormal in R2\mathbb{R}^2R2?
{(1,0),(0,1)}\{(1, 0), (0, 1)\}{(1,0),(0,1)}
{(1,1),(−1,1)}\{(1, 1), (-1, 1)\}{(1,1),(−1,1)}
{(1,0),(1,1)}\{(1, 0), (1, 1)\}{(1,0),(1,1)}
{(1/2,1/2),(1/2,−1/2)}\{(1/\sqrt{2}, 1/\sqrt{2}), (1/\sqrt{2}, -1/\sqrt{2})\}{(1/2,1/2),(1/2,−1/2)}