University of Illinois
University of Illinois Urbana Champaign: Chickscope Egg Math: Equations for an Ellipse
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.
Math Words
Math words.com: Foci of an Ellipse
The definition for foci for an ellipse is given and the definition for ellipse is given. Also gives a diagram and the equation for an ellipse in standard form.
Discovery Education
Discovery Education: Web Math: Graphing Ellipses
WebMath offers a java applet that allows you to input information about an ellipse, in one of four forms, and gives you the graph of the ellipse.
Math Words
Math words.com: Ellipse
Brief definition for ellipse. The standard form for the equation of an ellipse is given also.
University of Illinois
University of Illinois Urbana Champaign: Chickscope Egg Math: The Shape of an Egg
Drawing a perfect ellipse with pins and string is demonstrated with a java simulation.
University of Illinois
University of Illinois Urbana Champaign: Chickscope Eggmath: The Shape of an Egg
An interactive page offering a view of a rotating egg, information on rotational symmetry, and definitions of related topics.
National Council of Teachers of Mathematics
The Math Forum: Analytic Geometry Formulas, Ellipses
A brief overview from the Math Forum on calculating various measures of segments, like major and minor axes and distance from focus to center, is given. Additionally, equations of ellipse in general and standard forms are listed.
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Equations of Conics
Posed with a student question about equations of conics, Dr. Math provides some insight on the standard form of parabolas, ellipses, and hyperbolas. One example is shown.
Purple Math
Purplemath: Conics: An Overview
Introduces the basics of conics in algebra, including a flow-chart for determining which sort of conic is represented by a given equation.
NASA
Nasa: Kepler's Third Law
This site from NASA states Kepler's third law of motion and extends it to develop an equation for the velocity of an orbiting planet.
Other
The Krell Institute: Project: Rotation of Axes
This resource provides an explanation of the equation for rotation of axes with conic sections includes an example with an ellipse.
CK-12 Foundation
Ck 12: Analysis: Explicit Formulas
[Free Registration/Login may be required to access all resource tools.] In this lesson students learn about explicit formulas for identifying terms of a sequence without knowing the preceding term. Students examine guided notes, review...