CUET Preparation Today
The angle between 2 vectors $\vec{a}$ and $\vec{b}$ with magnitude 1 and 2 respectively when $\vec{a} . \vec{b}=1$ is: |
$\frac{\pi}{6}$ $\frac{\pi}{3}$ $\frac{\pi}{2}$ $\frac{\pi}{4}$ |
$\frac{\pi}{3}$ |
The correct answer is Option (2) → $\frac{\pi}{3}$ $|\vec{a}|=1$, $|\vec{b}|=2$ so $\vec a.\vec b=|\vec{a}||\vec{b}|\cos θ$ $⇒1=1×2\cos θ⇒\cos θ=\frac{1}{2}$ $θ=\frac{\pi}{3}$ |
