The set of all , for which the vector and are inclined at an obtuse angle for all is :
- (A)
- (B)
- (C)✓ Correct
- (D)
Answer: (C)
Solution
for all . This quadratic in is negative for all iff its leading coefficient and discriminant : . Including (then ) gives . Option (3).
JEE Main · 2024 · 08 Apr 2024 · Shift 1 · Single correct option