Find out how an astroid is related to the ellipse at this math page. This page starts with describing how an astroid may be created easily with two concentric circles with a given ratio, the site then goes into details regarding the...

This animated tutorial gives the focus/directrix definition of a conic. Also includes specific definition for the parabola, ellipse, and hyperbola. Includes equations for the conics in both rectangular and polar coordinates.

This site from MathWorld is a good site explaining the ellipse that is in-depth and complete with pictures, charts, formulas and examples. A helpful, and informative site on the subject. Links are also provided for additional information.

Drawing a perfect ellipse with pins and string is demonstrated with a java simulation.

Investigation and discussion of the way "Pin and string construction," works in producing an ellipse. Works through the corresponding equations in a well-ordered way.

The University of St. Andrews offers a comprehensive and detailed site explaining the ellipse.

This WebMath site shows how to graph ellipses. Click on the form of ellipse equation you need to plot the ellipse.

This WebMath site shows how to graph ellipses. Click on the form of ellipse equation you need to plot the ellipse.

This WebMath site shows how to graph ellipses. Click on the form of ellipse equation you need to plot the ellipse.

This WebMath site shows how to graph ellipses. Click on the form of ellipse equation you need to plot the ellipse.

Basic definitions are given for foci, focus, and other terms related to the focus (foci).

View a simple graph of an ellipse and a photo showing how the ellipse intersects a cone.

View a simple graph of an ellipse and a photo showing how the ellipse intersects a cone.

Good site explaining the laws of planetary motion and ellipses

Resource provides an introduction to conics. A picture of each conic, the definition, and a brief discussion about the standard form of conic equations are given, along with encouragement to master conics.

Based off of the hit television show NUMB3RS, this lesson introduces students to the ellipse, especially it's foci. Students create an ellipse on wax paper by repeatedly folding a circle to meet a chosen internal point. When finished,...

This site from NASA provides biographical details about the lives of Tycho Brahe and Johannes Kepler. Discusses Kepler's successes at developing laws of planeatry motion. States the three laws and discusses each one individually....

In an episode of "Numb3rs" called "Harvest," Charlie figures out that an ambulance did not travel in a straight line. Knowing the starting point and the ending point (the foci), Charlie finds the ellipse that shows all the possible...

These questions ask students to write the equations of conic sections given a variety of information. Students are also asked to find the foci of an ellipse and the asymptotes of a hyperbola. Solutions and explanations are included.

This Learn Check file is a review of writing conic sections given the graph of a conic section. Students are asked to use the graphs to write the equations for a ellipse, circle, parabola, and hyperbola.

Students investigate the definition of a parabola through one of its geometric definitions. They study conic sections. They examine an ellipse as a locus of points such that the sum of distances from the foci to the traced path is constant.

Students investigate the reflective properties of the parabola, the ellipse, and the hyperbola. They will look at applications that relate to both the collection of incoming signals and signals that are emitted from a source and...

In Spanish. Learn more about the ellipse, hyperbola and the parabola with these interactive activities.

Provides the locus of points, dominant axis and equation, discriminant, center, vertex, focus, directrix, and asymptotes for the parabola, the ellipse, and the hyperbola.