[Moderator note: Post moved from New Member Introductions forum, so no template] I am having trouble understanding how to multiply unit vectors. I know that: (please excuse the notation) i^×j^ = k^ j^×k^ = i^ k^×i^ = j^ The question I am stuck on is: What is (i^×j^)×k^? So far I have (i^×j^) = k^, which would mean the above equation turns into k^×k^. I am supposed to represent the answer in unit vector form, but the only answers I can come up with are k^ squared or -1... What am I missing? All help is appreciated!