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 P: 3 hi! i'm new to the forums, and had a question that was more calculus-related than physics. i saw another post similar to this one, but it was incomplete and i couldn't get the answer with the information on it, any chance someone could help me out? The question is: "Find a unit vector with a positive first coordinate that's orthogonal to both 'a' and 'b' a=<1,8,1> b=<1,16,1>" the answer i got (which is only 1/3 right) was <1/8,0,-1/8> i've tried using cross products, and then dividing by the magnitude of the cross product to get the unit vector, but only get the j variable right, and not i and k. i've also tried projecting a onto b (and visa versa) to find parallel vectors, and then trying the cross product again, but still can't seem to get the right answer. Any ideas?