Let and be three vectors such that is coplanar with and . If the vector is perpendicular to and , then is equal to
- (A)
- (B)18
- (C)16
- (D)✓ Correct
Answer: (D)
Solution
Since is coplanar with and , write .
, , .
Perpendicularity gives
The condition gives
Substituting :
Then
, , .
Perpendicularity gives
The condition gives
Substituting :
Then
JEE Main · 2025 · 24 Jan 2025 · Shift 1 · Single correct option