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Vector help for exam review

  1. Oct 17, 2011 #1
    The question is:
    let V1=(2,2,0), V2=(-1,2,1), V3-(1,1,4). There three vectors determine a parallelepiped. P draw it.
    (a) (this is the one that is giving me trouble) Determine the length of its main diagonal. (from origin to opposite vertex).

    I can't seem to figure out what it means from the origin to the opposite vertex. I've drawn the graph and originally I thought I would have to take the determine of two vectors then find the length of it. I'm just pretty lost here. Once I get this part and I know what its asking of me I can get the other problems easily.
  2. jcsd
  3. Oct 17, 2011 #2


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    The origin is (0,0,0). The opposite vertex is the point at the end of the vector V1+V2+v3 (with one end at the origin), that is (2,5,5).

    I assume you know how to get this length.
  4. Oct 18, 2011 #3
    thanks, that helped a lot
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