Let and . Let be a vector such that , and the angle between and be . Then is equal to :
- (A)
- (B)
- (C)2✓ Correct
- (D)5
Answer: (C)
Solution
First , of magnitude . From and the angle, , so . Also . Expanding gives , that is , so .
JEE Main · 2017 · 02 Apr 2017 · Offline · Single correct option