Q17: Given: a = i + j + k, a. b = 1 and a × b = j - k. Then, b is equal to A. -2i B. 2i + k C. 3j D. i how?
Last edited by mr fantastic; Feb 11th 2011 at 02:27 AM. Reason: Re-titled, deleted excessive ?'s in post, moved to correct subforum.
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An idea might be to start by defining so that you can get expressions for and , which you then should be able to solve simultaneously for ...
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