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Math Help - vectors

  1. #1
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    vectors

    If two vectors u and v fit the equation (u - v) times (u - v) = u times u + v times v, how must these vectors u and v be related? What familiar theorem does this equation represent?
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  2. #2
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    Is this the problem: \left( {u - v} \right) \cdot \left( {u - v} \right) = u \cdot u + v \cdot v?
    That is dot product, not times.
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  3. #3
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    Quote Originally Posted by Plato View Post
    Is this the problem: \left( {u - v} \right) \cdot \left( {u - v} \right) = u \cdot u + v \cdot v?
    That is dot product, not times.
    Yes it is. Sorry I didn't know how to do dots, so I just put the x in instead. I should have specified.

    Can you help me? =(
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  4. #4
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    \left( {u - v} \right) \cdot \left( {u - v} \right) = u \cdot u - 2u \cdot v + v \cdot v
    but if that is u \cdot u - 2u \cdot v + v \cdot v = u \cdot u + v \cdot v
    do you see that 2u \cdot v = 0?
    So what does that mean about u & v?
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