Describe a vectors v = [x y] that are orthogonal to u = [a b]. If u is not the zero vector, then v is a multiple of [a b]. If u is not the zero vector, then v is a multiple of [a -b]. If u is not the zero vector, then v is a multiple of [a -b]. If u is not the zero vector, then v is a multiple of [a -b]. If u is not the zero vector, then v is a multiple of [a + b a - b].