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Homework Help: Linear Algebra question

  1. Jan 11, 2007 #1
    1. The problem statement, all variables and given/known data

    Find a Cartesian equation for the line p + tv, where p=<2,5> and v=<-3,1>

    2. Relevant equations



    3. The attempt at a solution

    I know the vector form will look likse <2,5>+t<-3,1>. But I'm not sure how to use this information to find the equation of the line in y=mx+b form.
     
  2. jcsd
  3. Jan 11, 2007 #2
    Just substitute two points into the line y=mx+b to find m and b. Also, the slope m can be obtained immediately from the direction vector v.
     
  4. Jan 12, 2007 #3

    TD

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    Homework Helper

    Or, if you write the vector form in components, eliminate t from this system:

    [tex]
    \left\{ \begin{array}{l}
    x = 2 - 3t \\
    y = 5 + t \\
    \end{array} \right.
    [/tex]
     
  5. Jan 12, 2007 #4

    HallsofIvy

    User Avatar
    Science Advisor

    Now, solve one equation for t and (I recomment y= 5+ t) and substitute that into the other equation.
     
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