WOLFRAM|DEMONSTRATIONS PROJECT

Constructing a Parabola from Tangent Circles

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radius of inner circle
10
distance of inner circle from line
5
Let
C
be a circle that does not intersect a horizontal line
l
. Use the sliders to change the radius of
C
or the distance of
C
to
l
. The locus of the centers of the circles that are tangent to both
C
and
l
is a parabola.