TI-83 Plus Function Graphing 105
Chapter 3:Function Graphing

Getting Started: Graphing a Circle

Getting Started is a fast-paced introduction. Read the chapter for details.
Graph a circle of radius 10, centered on the origin in the standard viewing
window. To graph this circle, you must enter separate formulas for the upper and
lower portions of the circle. Then use ZSquare (zoom square) to adjust the
display and make the functions appear as a circle.
1. In Func mode, press o to display the Y= editor.
Press y ã‡ä 100 ¹ „ ¡ ¤ Í to
enter the expression Y=‡(100NX2), which
defines the top half of the circle.
The expression Y=L‡(100NX2) defines the
bottom half of the circle. On the TI-83 Plus, you
can define one function in terms of another. To
define Y2=LY1, press Ì to enter the negation
sign. Press ~ to display the VARS Y.VARS
menu. Then press Í to select 1:Function.
The FUNCTION secondary menu is displayed.
Press 1 to select 1:Y1.