Texas Instruments TI-83 PLUS - Manual (Page 171)

TI-83 Plus Polar Graphing 168
Defining and Displaying Polar Graphs
TI-83 Plus Graphing Mode Similarities
The steps for defining a polar graph are similar to the steps for defining a
function graph. Chapter 5 assumes that you are familiar with Chapter 3:
Function Graphing. Chapter 5 details aspects of polar graphing that differ
from function graphing.
Setting Polar Graphing Mode
To display the mode screen, press z . To graph polar equations, you
must select Pol graphing mode before you enter values for the window
variables and before you enter polar equations.
Displaying the Polar Y= Editor
After selecting Pol graphing mode, press o to display the polar
Y= editor.