Mathematics · JEE | VECTOR ALGEBRA

If \( \theta \) is the angle between two vectors \( \vec{a} \) and \( \vec{b} \), then \( \vec{a}\cdot\vec{b} \geq 0 \) only when:

1. A
   \( 0 < \theta < \pi \)
2. B
   \( 0 < \theta < \frac{\pi}{2} \)
3. C
   \( 0 \leq \theta \leq \frac{\pi}{2} \)
4. D
   \( 0 \leq \theta \leq \pi \)