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Re: intersection of two circles

  • To: mathgroup at smc.vnet.net
  • Subject: [mg105870] Re: [mg105850] intersection of two circles
  • From: Andrzej Kozlowski <akoz at mimuw.edu.pl>
  • Date: Tue, 22 Dec 2009 04:06:41 -0500 (EST)
  • References: <200912211201.HAA05285@smc.vnet.net>

On 21 Dec 2009, at 21:01, Felix wrote:

> Hey,
> I m already hours busy with trying to find a way to indicate the 
coordinates of the point(s) where two circles intersect.
> Does Mathematica have a function that gives me the points of 
intersection if my input are the coordinates (in 2D) and the radii.
> Thanks,
>
> Felix
>

In principle, of course.

eq1 = (x - 2)^2 + (y - 3)^2 == 4;eq2 = (x - 1)^2 + (y - 4)^2 ===
 9;

 {x, y} /. Solve[{eq1, eq2}]

 {{(1/4)*(11 - Sqrt[23]), (1/4)*(9 - Sqrt[23])},
   {(1/4)*(11 + Sqrt[23]), (1/4)*(9 + Sqrt[23])}}

??

Andrzej Kozlowski


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