Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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

    symbolipoint

    User Avatar
    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.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook