Texas Instruments TI-73VSC Teachers Guide - Page 23

18

Using the TI-73: A Guide

for Teachers

Patterns and Relations

© 1998 T

EXAS

I

NSTRUMENTS

I

NCORPORATED

14. Turn off

STAT PLOTS

, and then display the graph.

-

e

Q

b

*

15. Ask:

What do you notice about the graph on the screen?

What is the value of Y when X is 57? How can you

find out?

(Press

)

to see the values on the graph.

If you are not tracing whole number values for

X

,

estimate the value of

Y

by rounding the decimal.)

What will Y equal when X is 57?

(To find the whole

number value, press

R

J

b

.)

Is this the same value you found earlier when you

added 3 to each previous term? When you used the

@

key? When you used the

b

key?

16. Since the

X

values in the table of values for the

equation depend on some initial settings in the

TABLE

SETUP,

do the following.

a.

Access the

TABLE SETUP

screen.

-

f

(above the

'

key)

Have students sketch the

graph on graph paper for

further discussions later

(slope, intercepts, how

does it describe the

situation in the problem?,

etc.).

b.

Make sure the screen looks like the one shown at

the right (

TblStart=0,

@

Tbl=1, Indpnt: Auto, Depend:

Auto

).

17. Use the TI-73 to show a table of values for the

equation.

-

i

(above the

*

key)

18. Compare the table on the TI-73 with the T-chart in the

first part of the activity. Ask:

What value does the table give for X = 57?

How does this compare to the value you computed

earlier for X = 57?

What do the X values in the table represent?

(the

length of the wall)

What do the numbers in the

Y

1

column represent?

(the number of beams)

19. Enter the second equation

Y = 4 + 3(X - 1)

in

Y

2

, and

then graph it.

&

#

to

Y

2

Q

\

[

D

I

T

Y

E

*

Ask:

Do you see 2 lines? Why not?

Texas Instruments TI-73VSC Teachers Guide - Page 23

Y = 4 + 3X - 1

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