Chapter 3: Function Graphing 92
Chapter 3:Chapter 3:Chapter 3:Chapter 3:Function GraphingFunction GraphingFunction GraphingFunction Graphing

Getting Started: Graphing a Circle

Getting Started: Graphing a CircleGetting Started: Graphing a Circle

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 C 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-84 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 VARSY-VARS menu. Then press
Í to select 1:Function. The FUNCTION
secondary menu is displayed. Press 1 to select
1:Y1.