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Conic Sections. The Ellipse Part A. Ellipse. Another conic section formed by a plane intersecting a cone Ellipse formed when. Definition of Ellipse. Set of all points in the plane … Sum of distances from two fixed points (foci) is a positive constant. Definition of Ellipse.
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Conic Sections The EllipsePart A
Ellipse • Another conicsection formedby a plane intersecting acone • Ellipse formed when
Definition of Ellipse • Set of all points in the plane … • Sum of distances from two fixed points(foci) is a positive constant
Definition of Ellipse • Definition demonstrated by using two tacks and a length of string to draw an ellipse
Graph of an Ellipse Note various parts of an ellipse
Deriving the Formula • Note • Why? • Write withdist. formula • Simplify
Major Axis on y-Axis • Standard form of equation becomes • In both cases • Length of major axis = 2a • Length of minor axis = 2b Link to Animated Web Page
Using the Equation • Given an ellipse with equation • Determine foci • Determine values for a,b, and c • Sketch the graph
Find the Equation • Given that an ellipse … • Has its center at (0,0) • Has a minor axis of length 6 • Has foci at (0,4) and (0,-4) • What is the equation?
Ellipses with Center at (h,k) • When major axis parallelto x-axis equation can be shown to be
Ellipses with Center at (h,k) • When major axis parallelto y-axis equation can be shown to be
Find Vertices, Foci • Given the following equations, find the vertices and foci of these ellipses centered at (h, k)
Find the Equation • Consider an ellipse with • Center at (0,3) • Minor axis of length 4 • Focci at (0,0) and (0,6) • What is the equation?
Assignment • Ellipses A • 1 – 43 Odd