Operation Manual

Chapter 4: Parametric Graphing 98
Defining and Editing Parametric Equations
To define or edit a parametric equation, follow the steps in Chapter 3 for defining a function or editing
a function. The independent variable in a parametric equation is T. In parametric graphing mode, you
can enter the parametric variable T in either of two ways.
• Press „.
• Press ƒ [
T].
Two components, X and Y, define a single parametric equation. You must define both of them.
Selecting and Deselecting Parametric Equations
The TI-84 Plus C graphs only the selected parametric equations. In the Y= editor, a parametric equation
is selected when the
= signs of both the X and Y components are highlighted. You may select any or all
of the equations X1T and Y1T through X6T and Y6T.
To change the selection status, move the cursor onto the
= sign of either the X or Y component and
press Í. The status of both the X and Y components is changed.
Setting Window Variables
To display the window variable values, press p. These variables define the viewing window. The
values below are defaults for parametric graphing in Radian angle mode.
Note: To ensure that sufficient points are plotted, you may want to change the
T window variables.
Setting the Graph Format
To display the current graph format settings, press y.. Chapter 3 describes the format settings
in detail. The other graphing modes share these format settings; Seq graphing mode has an additional
axes format setting.
è Thick A thick solid line connects plotted points.
é Above Shading covers the area above the graph
ê Below Shading covers the area below the graph
ë Path A circular cursor traces the leading edge of the graph and
draws a path
ì Animate A circular cursor traces the leading edge of the graph without
drawing a path
Dot-Thick A dot (3 x 3 pixel) enhances the view around the actual
plotted point; this is the default in Dot mode.
í Dot-Thin A small dot (1 x1 pixel) represents each plotted point.
Tmin=0
Smallest T value to evaluate
Tmax=6.2831853...
Largest T value to evaluate (2p)
Tstep=.1308996...
T value increment (pà24)
Xmin=L10
Smallest X value to be displayed
Xmax=10
Largest X value to be displayed
Xscl=1
Spacing between the X tick marks
Ymin=L10
Smallest Y value to be displayed
Ymax=10
Largest Y value to be displayed
Yscl=1
Spacing between the Y tick marks
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