Question

If a, b, c are three non-coplanar mutually perpendicular unit vectors, then [a b c] is 

A. ±1 

B. 0

C. -2

D. 2

Answer 1

Correct option is  A. ±1

Here, \(\vec a\perp\vec b\perp \vec c\) and \(|\vec a|=|\vec b| = |\vec c| = 1.\)

⇒ \(\vec a\times\vec b||\vec c\)

⇒  angle between \(\vec a\times\vec b\) and  \(\vec c\) is  \(\theta\) = 0° or \(\theta\) = 180°.