Operation Manual

Chapter 4: Parametric Graphing 99
Displaying a Graph
When you press s, the TI-84 Plus C plots the selected parametric equations. It evaluates the X and Y
components for each value of T (from Tmin to Tmax in intervals of Tstep), and then plots each point
defined by X and Y. The window variables define the viewing window.
As the graph is plotted, X, Y, and T are updated.
Smart Graph (see Chapter 3) applies to parametric graphs.
Window Variables and Y.VARS Menus
You can perform these actions from the home screen or a program.
• Access functions by using the name of the
X or Y component of the equation as a variable.
• Store parametric equations.
• Select or deselect parametric equations.
• Store values directly to window variables.
Exploring Parametric Graphs
Free-Moving Cursor
The free-moving cursor in parametric graphing works the same as in Func graphing.
In
RectGC format, moving the cursor updates the values of X and Y; if CoordOn format is selected, X
and Y are displayed.
In
PolarGC format, X, Y, R, and q are updated; if CoordOn format is selected, R and q are displayed.
TRACE
To activate TRACE, press r. When TRACE is active, you can move the trace cursor along the graph of
the equation one
Tste p at a time. When you begin a trace, the trace cursor is on the first selected
function at
Tmin. If ExprOn is selected, then the function is displayed.