Correct option: (A) |A➙ + B➙|2 – |A➙ – B➙|2 = 2 (A2 + B2)
Explanation:
Addition of two square of norm of vectors follow parauelogram law as
|A➙|2 + |B➙|2 = (1/2) (|A➙ + B➙|2 – |A➙ – B➙|2)
∴ 2 [|A➙|2 + |B➙|2] = |A➙ + B➙|2 – |A➙ – B➙|2
i.e. 2(A2 + B2) = |A➙ + B➙|2 – |A➙ – B➙|2