Recent content by CarlisleLes

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    Undergrad Deriving Descriptions of Conic Sections from Fundamental Definition

    I found an answer at http://www.clowder.net/hop/Dandelin/Dandelin.html. Thanks everyone.
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    Undergrad Deriving Descriptions of Conic Sections from Fundamental Definition

    I have read that a dozen times. It doesn't explain the directrix derivation - just says it's possible to do so.
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    Undergrad Deriving Descriptions of Conic Sections from Fundamental Definition

    Everyone knows by now that a conic section is the figure formed when a plane intersects a right circular cone. Most everyone also knows that there are many different ways to describe a conic, geometrically and algebraically. What one seldom sees is the derivation of those descriptions from the...