MCQ
The angle between two vectors $2 \hat{i} \quad 3 \hat{j} \quad \hat{k}$ and $\hat{i} \quad 2 \hat{j} \quad 4 \hat{k}$ is
- A$0^{\circ}$
- ✓$90^{\circ}$
- C$180^{\circ}$
- DNone of the above
✓
Answer
Correct option: B.
$90^{\circ}$
(b) $\cos \theta=\frac{\vec{A} \cdot \vec{B}}{|\vec{A}||\vec{B}|}=\frac{-2+6-4{\sqrt{14} \sqrt{21}}=0 \therefore \theta=90^{\circ}$
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