Texas Instruments TI-89, TI-92

134 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 134 of 6

Steps

TI-89

Keystrokes

›

TI-92 Plus

Keystrokes Display

1. Display the

MODE dialog box.

For Graph mode, select POLAR.

For Angle mode, select RADIAN.

DDDB1

2. Display and clear the Y= Editor.

Then define the polar equation

r1(q) = A sin Bq.

Enter 8 and 2.5 for A and B,

respectively.

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3. Select the

ZoomStd viewing

window, which graphs the

equation.

• The graph shows only five rose

petals.

− In the standard viewing window,

the Window variable qmax = 2p.

The remaining petals have q

values greater than 2p.

• The rose does not appear

symmetrical.

− Both the x and y axes range from

ì10 to 10. However, this range is

spread over a longer distance

along the x axis than the y axis.

„6„6

4. Display the Window Editor, and

change qmax to 4p.

p will be evaluated to a number

when you leave the Window Editor.

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5. Select

ZoomSqr, which regraphs

the equation.

ZoomSqr increases the range along

the x axis so that the graph is shown

in correct proportion.

„5„5

6. You can change values for A and

B as necessary and regraph the

equation.

Preview of Polar Graphing

The graph of the polar equation A sin Bq forms the shape of a rose. Graph the rose for

A=8 and B=2.5. Then explore the appearance of the rose for other values of A and B.