1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
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: Find the coordinated of a point.

  1. Mar 2, 2013 #1
    1. The problem statement, all variables and given/known data

    Find the coordinates of point Q if Q divides the line AP in the ratio a^{2}:b^{2}, b>a.

    2. Relevant equations


    3. The attempt at a solution

    I found the equation of PA which was y-btanθ=(bsecθ)/(asecθ)(x-asecθ) than I didn't know what to do.
    This is supposed to be a very easy question but I'm not good at conics, I'm much better at calculus/analysis :)
  2. jcsd
  3. Mar 2, 2013 #2


    User Avatar
    Science Advisor

    To say that Q is such that it divides the interval, AP, in the ratio x:y means that we must have |AQ|/|AP|= x/(x+y) and, as a result, |QP|/|AP|= y/(x+y).

    Here, |AB| is the length of the interval so that we must have |AQ|+ |QP|= |AP|.

    From your picture, as well as your refernce to "conics", it appears that A and B are the vertices of an hyperbola and P a point on that hyperbola but you don't seem to have used that fact anywhere.
    Last edited by a moderator: Mar 2, 2013
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted