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Chapter 4: Graphing Features
5. Graphing Parametric Equations
A two-dimensional parametric equation assumes that both X and Y are represented
by functions in a third variable T. When set in parametric graphing mode, the calculator
automatically sets up the Graph Equation Entry screen to take one set of X and Y per
each graph, with the equation’s right side variable to be set as “T”.
Example
• Draw a graph:
x(t) = 16cos(t), y(t) = 9sin(t)
.
1. Press
@
;
to enter the SETUP menu.
2. Press
E
to select
E
COORD, then
2
to
select
2 Param.
Be sure that the other
settings are as shown on the
right.
To exit the SETUP menu, press
C
.
3. Press
Y
to go to the Graph Equation Entry window.
4. Enter
16cos(t)
for
X1T=.
Press
E
when done
entering.
5. Enter
9sin(t)
for
Y1T=. Press
E
when done entering.
Note: The right side variable is automatically set to “T”. When the
X
key is pressed within the Graph Equation Entry window, it will enter
the variable “T”.
6. Press
G
to draw the graph.
7. If the graph line extends
beyond the screen, press
Z
and select
A ZOOM
then
1 AUTO.
Use
3 IN or 4 OUT of the A
ZOOM to adjust the drawing size.
You can also set the drawing size in the WINDOW menu by
determining the maximum and minimum values of T, X and Y.
