Let and . If and the length of the projection of on is , then is equal to :
- (A)9
- (B)6
- (C)4
- (D)12✓ Correct
Answer: (D)
Solution
Compute . The condition gives , so and . The length of the projection of on is . Therefore .
JEE Main · 2026 · 23 Jan 2026 · Shift 2 · Single correct option