Question

Given that and . What can you conclude about the vectors ?

Answer 1

It is given that a → . b → =0 and a → × b → =0.

Since, a → . b → =0.

So, either a → =0 or b → =0 or a → is perpendicular to b → .

Since, a → × b → =0.

So, either a → =0 or b → =0 or a → is parallel to b → .

It is impossible for two vectors to be parallel and perpendicular at the same time.

Thus, if a → . b → =0 and a → × b → =0 , then a → =0 or b → =0.