Texas Instruments PLUS TI-89 - Manual (Page 153)

136 Chapter 8: Polar Graphing
08POLAR.DOC TI-89/TI-92 Plus: Polar Graphing (English) Susan Gullord Revised: 02/23/01 10:57 AM Printed: 02/23/01 2:14 PM Page 136 of 6
Use 3 to set Graph = POLAR before you define equations or set
Window variables. The Y= Editor and the Window Editor let you
enter information for the current
Graph mode setting only.
You should also set the Angle mode to the units ( RADIAN or DEGREE )
you want to use for q.
The Y= Editor maintains an independent function list for each Graph
mode setting. For example, suppose:
¦ In FUNCTION graphing mode, you define a set of y(x) functions.
You change to POLAR graphing mode and define a set of r( q )
equations.
¦ When you return to FUNCTION graphing mode, your y(x) functions
are still defined in the Y= Editor. When you return to POLAR
graphing mode, your r( q ) equations are still defined.
The Above and Below styles are not available for polar equations and
are dimmed on the Y= Editor’s Style toolbar menu.
Differences in Polar and Function Graphing
This chapter assumes that you already know how to graph y(x)
functions as described in Chapter 6: Basic Function Graphing.
This section describes the differences that apply to polar
equations.
Setting the
Graph Mode
Defining Polar
Equations on the
Y= Editor
Tip: You can use the Define
command from the Home
screen (see Appendix A) to
define functions and
equations for any graphing
mode, regardless of the
current mode.
Selecting the
Display Style
You can define polar
equations for r1(
q )
through r99( q ).