For three unit vectors satisfying
and
,
the positive value of k is :
and
,
the positive value of k is :
- (A)3
- (B)6
- (C)4
- (D)5✓ Correct
Answer: (D)
Solution
Expanding, , so . Then , so and . Hence , whose positive solution is .
JEE Main · 2026 · 28 Jan 2026 · Shift 1 · Single correct option