Let $\vec a$ be a unit vector perpendicular to unit vectors $\vec b$ and $\vec c$ and if the angle between $\vec b$ and $\vec c$ is $α$, then $\vec b×\vec c$ is
Answer & explanation
Correct answer: option 3
We have,
$\vec a=±\frac{\vec b×\vec c}{|\vec b×\vec c|}$
$⇒\vec b×\vec c=±|\vec b×\vec c|\vec a=±(\sin α)\vec a$ $[∵|\vec b×\vec c|=\sin α]$