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This chapter delves into conic sections, exploring their definitions, properties, and equations. A conic is formed by the intersection of a plane and a double-napped cone, resulting in shapes such as circles, ellipses, parabolas, and hyperbolas. We discuss degenerate conics, the algebraic definitions of each conic type, and the standard equations. Key objectives include recognizing, graphing, and writing equations for conics centered at the origin, and finding focal points. Examples demonstrate how to determine the standard form from general equations.
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Mathematics 116Bittinger • Chapter 7 • Conics
Mathematics 116 • Conics • A conic is the intersection of a plane an a double-napped cone.
Degenerate Conic • Degenerate conic – plane passes through the vertex • Point • Line • Two intersecting lines
Definition of Conic • Locus (collection) of points satisfying a certain geometric property.
Circle • A circle is the set of all points (x,y) that are equidistant from a fixed point (h,k) • The fixed point is the center. • The fixed distance is the radius
Algebraic def of Circle • Center is (h,k) • Radius is r
Def: Parabola • A parabola is the set of all points (x,y) that are equidistant from a fixed line, the directrix, and a fixed point, the focus, not on the line.
Standard Equation of ParabolaVertex at Origin • Vertex at (0,0) • Directrix y = -p • Vertical axis of symmetry
Standard Equation of ParabolaOpening left and right • Vertex: (0,0O • Directrix: x = -p • Axis of symmetry is horizontal
Willa Cather – U.S. novelist (1873-1947) • “The higher processes are all simplification.”
Definition: Ellipse • An ellipse is the set of all points (x,y), the sum of whose distances from two distinct points (foci) is a constant.
Standard Equation of EllipseCenter at Origin • Major or focal axis is horizontal
Standard Equation of EllipseCenter at Origin • Focal axis is vertical
Definition: hyperbola • A hyperbola is the set of all points (x,y) in a plane, the difference whose distances from two distinct fixed points (foci) is a positive constant.
Standard Equation of Hyperbolaopening up and downcentered at origin
Objective – Conics centered at origin • Recognize, graph and write equations of • Circle • Parabola • Ellipse • Hyperbola • Find focal points
Rose Hoffman – elementary schoolteacher • “Discipline is the keynote to learning. Discipline has been the great factor in my life.”
Mathematics 116 • Translations • Of • Conics
Circle • Center at (h,k) radius = r
Objective • Recognize equations of conics that have been shifted vertically and/or horizontally in the plane.
Objective • Find the standard form of a conic – circle, parabola, ellipse, or hyperbola given general algebraic equation.
Example • Determine standard form – sketch • Find domain, range, focal points
Example - problem • Determine standard form – sketch • Find domain, range, focal points
Winston Churchill • “It’s not enough that we do our best; sometimes we have to do what’s required.”