Dandelin Sphere for the Parabola

​
cone angle
0.785398
sphere radius
1
sphere
contact circle
conic
focus
directrix
The parabola can be defined as the curve formed by the intersection of a cone with a plane parallel to a line on the cone passing through the origin. In this Demonstration, a Dandelin sphere shows the relationship between a parabola and its focus and directrix.

References

[1] L. Piegl and W. Tiller, The NURBS Book, 2nd ed., New York: Springer, 1997.
[2] C. Zwikker, The Advanced Geometry of Plane Curves and Their Applications, New York: Dover, 1963.

External Links

Dandelin Spheres (Wolfram MathWorld)
Parabola (Wolfram MathWorld)

Permanent Citation

Jan Mangaldan
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​"Dandelin Sphere for the Parabola"​
​http://demonstrations.wolfram.com/DandelinSphereForTheParabola/​
​Wolfram Demonstrations Project​
​Published: April 28, 2020