Mark the correct alternative in each of the following:
Let and be three non-zero vectors such that c⃗ is a unit vector perpendicular to both a⃗ and b⃗ . If the angle between a⃗ and b⃗ is, then is equal to
(∵ c⃗ is perpendicular to a⃗ and b⃗ ⇒ angle is 0)
(∵ c⃗ is unit vector )