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Setting the graph format, Displaying the graph, Using graph tools in param graphing mode – Texas Instruments TI-86 User Manual

Page 140: The free-moving cursor, Tracing a parametric function

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Chapter 9: Parametric Graphing

09PARA.DOC TI-86, Chap 9, US English Bob Fedorisko Revised: 02/13/01 2:27 PM Printed: 02/13/01 3:02 PM Page 128 of 8

09PARA.DOC TI-86, Chap 9, US English Bob Fedorisko Revised: 02/13/01 2:27 PM Printed: 02/13/01 3:02 PM Page 128 of 8

Setting the Graph Format

To display the format screen in

Param

graphing mode, select

FORMT

from the

GRAPH

menu

(6 / (). Chapter 5 describes the format settings. The TI

-86 retains in memory

separate format settings for

Func

,

Pol

,

Param

, and

DifEq

graphing modes.

Displaying the Graph

To plot the selected parametric equations, you can select

GRAPH

,

TRACE

,

EVAL

,

RCGDB

, or

a

ZOOM

,

MATH

,

DRAW

, or

RCPIC

operation. The TI

-86 evaluates

x

and

y

for each value of

t

(from

tMin

to

tMax

in intervals of

tStep

) and then plots each point defined by

x

and

y

. As the

graph is plotted, the variables

x

,

y

, and

t

are updated.

Using Graph Tools in Param Graphing Mode

The Free-Moving Cursor

The free-moving cursor in

Param

graphing works the same as in

Func

graphing.

In

RectGC

format, moving the cursor updates the values of

x

and

y

.; if

CoordOn

format is

selected,

x

and

y

are displayed.

In

PolarGC

format, moving the cursor updates

x

,

y

,

r

, and

q

; if

CoordOn

format is

selected,

r

and

q

are displayed.

Tracing a Parametric Function

To begin a trace, select

TRACE

from the

GRAPH

menu (6 )). When you begin a trace,

the trace cursor is on the first selected function at

tMin

.

In

RectGC

format, moving the trace cursor updates the values of

x

,

y

, and

t

; if

CoordOn

format is selected,

t

,

x

, and

y

and are displayed.

DrawLine

graph format

typically displays a more
meaningful parametric graph
than DrawDot graphing
format.