Texas Instruments TI-85 User Manual

Page 8

B-8

TI-85/TI-86 Graphing Calculators

1.1.4 AUTOMATICALLY CHANGING THE VIEW OF THE GRAPH

If your view

of the graph is not good or if you do not see the graph, change the view using the built-in
autoscaling feature of your calculator. This option will automatically find a view to see a l l
the functions that you have turned on in the graphing list.

Be sure the function you are graphing, y = 1000(1 + 0.05)

, is entered in the

location of t h e

y(x)=

list. (Delete all other functions that may be entered in other locations.) Before doing

what follows, access the graphics menu with

GRAPH

To access the range on the TI-85 (called the window on

the TI-86), press

. Set

xMin

to 0 and

xMax

to 10. (It does

not matter what values are set in the

yMin

and

yMax

positions.) Press

(

ZOOM

)

(

ZFIT

) .

Your calculator automatically sets a vertical view
(based on the

xMin

and

xMax

you set) and draws a

graph of the function.

1.1.5 TRACING

You can display the coordinates of certain points on the graph by tracing.

The x-values shown when you trace depend on the horizontal view that you choose, and t h e
y-values are calculated by substituting the x-values into the equation that is being graphed.

With the graph on the screen, press

(

TRACE

)

and use

to move the trace cursor to the right

and

to move the trace cursor to the left.

The number

in the upper right hand corner of the

screen tells you that you are tracing on the equation
in

Trace past the edge of the screen and notice that even
though you cannot see the trace cursor, x and y values
of points on the line are still displayed at the bottom
of the screen. Also notice that the graph scrolls to the
left or right as you move the cursor past the edge of
the current viewing screen.

1.1.6 ESTIMATING OUTPUTS

You can estimate outputs from the graph using

TRACE

. I t

is important to realize that such outputs are never exact values unless the displayed x-value
is identically the same as the value of the input variable.