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Homework Help: Parametric equation

  1. May 18, 2008 #1
    1. The problem statement, all variables and given/known data

    Find parametric equations for the line in which the planes 3x − 6y − 2z = 15
    and 2x + y − 2z = 5 intersect.


    2. Relevant equations



    3. The attempt at a solution

    <2, 1, -2> - <3, -6, -2> = <-1, 7, 0>

    x = 2 - t, y = 1 + 7t, z = -2

    Did I do this correctly??
     
  2. jcsd
  3. May 18, 2008 #2

    Dick

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    Uh, no. Put the solution back into your two line equations. Does it work? I don't think so. Where did you find this 'solution method'? I think you should maybe try and find one that does.
     
  4. May 19, 2008 #3
    <3, -6, -2> X <2, 1, -2> = <14, 2, 15>

    Then set z to 0 to get x = 3, y = -1 ==> <3, -1, 0>

    x = 3 + 14t
    y = -1 + 2t
    z = 15t
     
  5. May 19, 2008 #4

    Dick

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    Better. Did you check by substituting your result back into the plane equations?
     
  6. May 19, 2008 #5
    yes it worked, got 5 and 15
     
  7. May 19, 2008 #6

    Dick

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    Good!
     
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