Parametric Graphing 353
„ Zoom Works just as it does for function graphs, with the
following exceptions:
•Only x (xmin, xmax, xscl) and y (ymin, ymax, yscl)
Window variables are affected.
• The t Window variables (tmin, tmax, tstep) are not
affected unless you select 6:ZoomStd (which sets
tmin= 0, tmax = 2 p, and tstep = p/24).
…Trace Lets you move the cursor along a graph one tst ep at a
time.
• When you begin a trace, the cursor is on the first
selected parametric equation at tmin.
• QuickCenter applies to all directions. If you move the
cursor off the screen (top or bottom, left or right), press
¸ to center the viewing window on the cursor
location.
• Automatic panning is not available. If you move the
cursor off the left or right side of the screen, the TI-89
Titanium will not automatically pan the viewing window.
However, you can use QuickCenter.
‡Math Only 1:Value, 6:Derivatives, 9:Distance, A:Tangent,
and B:Arc are available for parametric graphs. These
tools are based on tvalues. For example:
•1:Value displays x and y values for a specified tvalue.
•6:Derivatives finds dy/dx, dy/dt, or dx/dt at a point
defined for a specified tvalue.
Tool For Parametric Graphs: