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Homework Help: Determining the equation of a curve

  1. Aug 30, 2008 #1
    1. The problem statement, all variables and given/known data

    A curve is traced by a point P (x,y) which moves such that its distance from the point A (-1,1) is three times its distance from the point B (2,-1). Determine the equation.

    2. Relevant equations

    3. The attempt at a solution

    used distance formulas to find A is the squareroot of 13 away from B.

    how do i find the curve
  2. jcsd
  3. Aug 30, 2008 #2
    I would try to translate what the problem says in words into equations.

    You're told that the distance from point A to point P is always 3 times the distance from point B to point P.

    So it seems to me that the way to proceed is to write down an expression for the distance from A to P and set it equal to the expression for the distance from B to P multiplied by 3.
  4. Aug 30, 2008 #3


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    Homework Helper
    Education Advisor
    Gold Member

    You should try applying the distance formula for the problem as you described it. That should help you to start.
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