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UNIT 10 : THE CONICS
LESSON 4: THE
PARABOLA HOMEWORK QUESTIONS
QUICK REVIEW:
Definition: Given a fixed point F and a fixed line d in the
plane. A parabola is the locus (set) of
points P in the plane, each of which is equidistant from the
fixed point F (the
focus) and the fixed
line d (the directrix). In the diagram |PF| = |PD| for any point P on the parabola.
The vertex V is the midpoint of the
perpendicular line segment from the
focus F to the directrix d .
![Text Box: Main Ideas for the Parabola:
· |PF| = |PD| for any point P on the parabola.
· The vertex is halfway between the focus and directrix
·
·
·
·
Definitions:
1. A chord is a line segment whose end points are on the curve.
2. A focal chord is a chord that passes through the focus.
3. The focal length is the distance from the vertex to the focus [VF]
4. The length of the focal chord perpendicular to the
axis of symmetry of the parabola is called the
focal width.](./parabolahw_files/image008.gif)
2. The arch of a large monument is in the shape of a parabola. If the span of the base is 20 m & the height is 12 m,
find the height of the arch at a point 4 m from the end of the arch.
Solutions:
2. The arch of a large monument is in the shape of a parabola. If the span of the base is 20 m & the height is 12 m,
find the height of the arch at a point 4 m from the end of the arch to the nearest tenth of a metre.
