Question

Which of the following vectors identities is/are false?(Below mentioned A, B and C are vectors, represented without vector sign on them)

• A. A + B = B + A
• B. A + B = - (B + A)
• C. (A + B) + C = A + (B + C)
• D. A + (B + C) = (A + C) + B

Answer 1

The correct option is B A + B = - (B + A)

Vector addition is commutative, i.e. A + B = B + A. Vector addition is also associative,
i.e. (A + B) + C = A + (B + C) = (A + C) + B.
Hence choice (b) is false.