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Homework Help: Linear Math Lines

  1. Nov 6, 2009 #1
    1. The problem statement, all variables and given/known data

    Find a and b such that the point (a,b,0) lies on the line passing through (-1,-1,6) and (-9,7,2)

    2. Relevant equations

    Basic line equations, from P to Q= Q-P..etc

    3. The attempt at a solution

    I keep getting the wrong answer, but I got a point at exactly P (-1,-1,6) and a direciton by doing Q-P...and solving for z=0...
  2. jcsd
  3. Nov 6, 2009 #2


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    Homework Helper

    so the line equation is
    L(t) = P + t*(Q-P)

    show your work, but soudns like you're heading in the right direction, solve for t, when z=0 as you say, then substitute back into line
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