If a, b, c are unit vectors such that a + b + c = 0, find the value of a.b + b.c + c.a.
If a, b, c are unit vectors such that a + b + c = 0, find the value of a.b + b.c + c.a.
- A. 3/2
- B. −3/2
- C. 0
- D. 3
Answer: B) −3/2
Explanation: |a + b + c|² = 0. Expanding: |a|² + |b|² + |c|² + 2(a.b + b.c + c.a) = 0. Since they are unit vectors, 1 + 1 + 1 + 2(a.b + b.c + c.a) = 0, leading to a.b + b.c + c.a = −3/2.
0 Answers
Log in to post your own answer or join the discussion.
No comments yet — start the discussion.