Question

What are the conditionsd for two vectors to be (i) parallel and (ii) perpendicular to each other?

Answer 1

(i) we know that vector A x B = (AB sinθ)n.

If two vectors are parallel,i.e., θ = 0, then vector A x B = 0 i.e., if two vectors are parallel, their cross- product must be zero.

(ii) Also vector A.B = AB cosθ

If two vectors are perpendicular, i.e., θ = 90°, then vector A.B = 0,i.e., if two vectors are perpendicular, their dot product must be zero.