This preview shows pages 1–14. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Horizontal Parabolas; notice that these curves do NOT represent functions. Example Find the focus and directrix of the parabola y 2 + 10 x = 0 and sketch the graph. 2 5 2 5 2 ) ( 4 10= == p x x y 2 5 2 5 : ), , ( == x D F Horizontal parabola Example Find the focus, vertex, and directrix of the parabola ( y+1) 2 =4(x 2) and sketch the graph. A horizontal and a vertical translation have taken place. The vertex is now (2, 1) and p = 1. The parabola opens left, so to find its focus we need to move 1 unit to the left of the vertex. Hence, F = (1, 1) The directrix is 1 unit to the right of the focus. Hence, D: x = 3. F V D Definitions A chord of a parabola is a straight line segment joining any two points on the curve. If a chord passes through the focus, it is called a focal chord. The focal width is the length of the focal chord perpendicular to the axis of symmetry. The focal width is always 4p ....
View Full
Document
 Fall '08
 GARDNER
 Calculus, PreCalculus, Cone, Conic Sections

Click to edit the document details