2 設向量 u∈R3 , v∈R3 , w∈R3 ,其中 R3 = {(x, y, z)|x∈R, y∈R, z∈R},下列何者錯誤? (A)u.(u×v) = 0 (B)u×v = v×u (C)u×(v×w) = (u.w) v ‒ (u.v)w (D)(u+3v)×v = u×v