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Homework Help: Write the parametric equation of the line

  1. Oct 24, 2009 #1
    1. The problem statement, all variables and given/known data

    Given a + b + c = 7, find a, b and c such that the point (a,b,c) lies on the line passing through the points (3,-4,0) and (2,-2,3)

    a =
    b =
    c =

    2. Relevant equations


    3. The attempt at a solution

    My instructor didn't go through this portion and I was wondering if I could get a little help.
    The way I understand the question is that there is a point between (3,-4,0) and (2,-2,3), such that they equal 7. I'm not sure how to go about this question.

    Any hints?

    Thanks in advance.
  2. jcsd
  3. Oct 24, 2009 #2


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    Homework Helper

    Re: Vectors

    If you meant ax+by+cz=7 and you want to find a,b,c such that (3,-4,0) and (2,-2,3) lie on this plane, then what would happen if you substituted a point (x0,y0,z0) which lies on the plane, into the equation of the plane?
  4. Oct 24, 2009 #3
    Re: Vectors

    Hmm but I typed the question exactly the way it is.

    And I'm not sure what you mean by substituting (x0,y0,z0)
    into the equation of the plane.
  5. Oct 24, 2009 #4


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    Gold Member

    Re: Vectors

    Write the parametric equation of the line, so you have expressions for x, y, and z in terms of t. Then set x + y + z = 7, figure out t and hence the required point.
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