If the angle between the vectors a=2^2 i+4 j+ k and b=7 i-2 j+ k is obtuse, then Option 1: (0,∞) Option 2: (0,1/2) Option 3: (-1,1) Option 4: (-∞,0) (1/2,∞)

The answer is '(0,1/2)'. View full solution:

CUET Mathematics - If the angle between the vectors a=2^2 i+4 j+ k and b=7 i-2 j+ k is obtuse, then | PYQs + Solutions

CUET Mathematics 2026 29th May Shift 1

Algebra

Medium

core

$\lambda \in (0,\infty)$

$\lambda \in \left(0,\dfrac{1}{2}\right)$

$\lambda \in (-1,1)$

$\lambda \in (-\infty,0) \cup \left(\dfrac{1}{2},\infty\right)$

✅ Correct Option: 2