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How do i get the point of intersection of a line and a circle?

  1. Aug 7, 2009 #1
    How do i get the point of intersection of a line and a circle.. I got lots of information on this topic, but my requirement is not matching..

    I got a line whose one end point lies at the origin of the circle.. and other end lies somewhere outside the circle.. Now i need the point of intersection of this line and circle..

    Any way to get the solution for this problem..??

    Thanks in advance
  2. jcsd
  3. Aug 7, 2009 #2
    Hi there,

    To get the intersection, you simply need to isolate one variable (let's say y) in one equation, and substitute it in the other. Then you have an equation with only one variable, which should be simple to solve. Once you have solve the equation, replace the solution in one of the first euqation to find the value of the second variable.

  4. Aug 7, 2009 #3
    You mean to say that, if,
    y = mx + b; and

    x^2 + y^2 = r^2

    are two equations, then subst y=mx+b in eqt of circle..??then solve this equation and then get value for x.. den subst x in y=mx+b and get value of y..

    am i right..???
  5. Aug 7, 2009 #4
    As simple as that.
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