Casio CFX-9850G PLUS, User'S Manual & Technical Reference

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Graphing a Conic Section
14 - 2
• Conic section graphs can be drawn in blue only.
• You cannot overwrite conic section graphs.
• The calculator automatically clears the screen before drawing a new conic
section graph.
• You can use trace, scroll, zoom, or sketch after graphing a conic section.
However, a conic section graph cannot be scrolled while using trace.
• You cannot incorporate graphing of a conic section into a program.
x -intercept A’ x -intercept A
y -intercept B’
y -intercept B
Focus F’ Focus F
Vertex A
Directrix
l
Axis of symmetry
Focus F (p, 0)
• A parabola is the locus of points equidistant from fixed line
l
and fixed point F
not on the line. Fixed point F is the “focus,” fixed line
l
is the “directrix,” the
horizontal line that passes through the focus directrix is the “axis of symme-
try,” the length of a straight line that intersects the parabola, passes through
the locus, and is parallel to fixed line
l
is the “latus rectum,” and point A where
the parabola intersects the axis of symmetry is the “vertex.”
• An ellipse is the locus of points the sum of the distances of each of which
from two fixed points F and F’ is constant. Points F and F’ are the “foci,”
points A, A’, B, and B’ where the ellipse intersects the
x
- and
y
-axes are the
“vertexes,” the
x
-coordinate values of vertexes A and A’ are called
x
-intercepts, and the
y
-coordinate values of vertexes B and B’ are called
y
-intercepts.
Latus rectum
CFX