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Homework Help: Tough vector geometry question.

  1. May 2, 2007 #1
    1. The problem statement, all variables and given/known data
    Line1: (x,y,x)=(2,1,-1) + t(-1,0,2)
    Line2: (x,y,x)=(1,1,3) + s(5,-6,-7)

    The lines L1 and L2 are skew; determine points Q and R on lines L1 and L2 respectively such that ||QR|| = 2

    2. The attempt at a solution
    I have no idea how to even approach this question! Can someone give me a clue? Please

    Thank you
    Last edited: May 2, 2007
  2. jcsd
  3. May 2, 2007 #2


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    Do you know how to find the closest distance between the two lines? I attempted to do it and get sqrt(16/21) which is less than 2. This means, if you imagine the geometry, that there are immensely many points on the two lines that are distance 2 apart. Are there any two in particular that you are interested in?
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