Operation Manual

Chapter 3: Function Graphing 84
Exploring Graphs with the Free-Moving Cursor
Free-Moving Cursor
When a graph is displayed, press |, ~, }, or † to move the cursor around the graph. When you first
display the graph, no cursor is visible. When you press |, ~, }, or †, the cursor moves from the center
of the viewing window.
As you move the cursor around the graph, the coordinate values of the cursor location are displayed at
the bottom of the screen if CoordOn format is selected. The Float/Fix decimal mode setting determines
the number of decimal digits displayed for the coordinate values.
To display the graph with no cursor and no coordinate values, press ‘ or Í. When you press |,
~, }, or †, the cursor moves from the same position.
Graphing Accuracy
The free-moving cursor moves from pixel to pixel on the screen. When you move the cursor to a pixel
that appears to be on the function, the cursor may be near, but not actually on, the function. The
coordinate value displayed at the bottom of the screen actually may not be a point on the function. To
move the cursor along a function, use r.
The coordinate values displayed as you move the cursor approximate actual math coordinates, accurate
to within the width and height of the pixel. As Xmin, Xmax, Ymin, and Ymax get closer together (as in
a Zoom In) graphing accuracy increases, and the coordinate values more closely approximate the math
coordinates.
Note: The graph screen is activly graphing X values between Xmin and Xmax, even if the
corresponding Y value is not in the graph area window. The busy indicator shows during the entire
window graphing.
Exploring Graphs with TRACE
Beginning a Trace
Use TRACE to move the cursor from one plotted point to the next along a function. To begin a trace,
press r. If the graph is not displayed already, press r to display it. The trace cursor is on the first
selected function in the Y= editor, at the middle X value on the screen. The cursor coordinates are
displayed at the bottom of the screen if
CoordOn format is selected. The Y= expression is displayed in
the top-left corner of the screen, if
ExprOn format is selected.
Moving the Trace Cursor
When the trace cursor moves along a function, the Y value is calculated from the X value; that is,
Y=Yn(X). If the function is undefined at an X value, the Y value is blank.
To move the TRACE cursor do this:
To the previous or next plotted point, press | or ~.
Five plotted points on a function (
Xres
affects this),
press y | or y ~.
To any valid X value on a function, enter a value, and then press Í.
From one function to another, press } or †.
Free-moving cursor appears to
be on the curve