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Solve the following.
If a⃗ and b⃗ are two non-zero vectors such that |a⃗ × b⃗| = a⃗ · b⃗, find the angle between a⃗ and…
If $\vec{a}$ and $\vec{b}$ are two non-zero vectors such that $|\vec{a} \times \vec{b}| = \vec{a} \cdot \vec{b}$, find the angle between $\vec{a}$ and $\vec{b}$.
Answer
Answer
$|\vec a\times\vec b| = |\vec a||\vec b|\sin\theta$ and $\vec a\cdot\vec b = |\vec a||\vec b|\cos\theta$.
Given $|\vec a\times\vec b| = \vec a\cdot\vec b$: $|\vec a||\vec b|\sin\theta = |\vec a||\vec b|\cos\theta$
Since $\vec a, \vec b$ are non-zero, $\tan\theta = 1$, so $\theta = \frac{\pi}{4}$.
Final answer: $\frac{\pi}{4}$