Let the position vectors of the points and be and . Let the set : The points A , B, C and D are coplanar}. Then is equal to
- (A)41✓ Correct
- (B)25
- (C)13
- (D)
Answer: (A)
Solution
Four points A, B, C, D are coplanar if .
The scalar triple product:
Expanding along the third row:
Solving gives or .
Therefore:
The scalar triple product:
Expanding along the third row:
Solving gives or .
Therefore:
JEE Main · 2023 · 06 Apr 2023 · Shift 1 · Single correct option