Texas Instruments TI-83-Plus - Page 56

Chapter 2: Linear Equations Section 1: Using Graphs & Tables
Topics in Algebra 1 © 2001 Texas Instruments Teacher Notes 2-9
³
Try-It!
é
on Your TI
.
83 Plus or TI
.
73
Tell students to:
•
Follow the steps exactly on the calculator, using the table feature to find the solution.
Example screen pictures are displayed on the worksheet for students to compare with the
calculator screen. This keystroke exercise lets students define
Y
1
=
2X+4.5 and Y
2
=7
.
•
Determine what the table settings should be for an exact solution and record them on their
worksheet.
Answer:
∆
Tbl=0.25
and
TblStart
=
1
.
•
Find the solution and record it.
Answer
:
Y
1
=Y
2
when
X=1.25
.
Solution Search Using X-Y Graphs:
Find the solution for the equation
X+3=1.7
.
Tell students to:
•
Estimate the solution and record it on their worksheets.
•
Follow the steps exactly on the calculator. Example screen pictures are displayed on the
worksheet for students to compare with the calculator screen. This keystroke exercise lets
students find the solution where
X+3=1.7
.
•
Record the solution and explain their answers on the worksheet after step 6.
Answers will vary. Student estimates using number sense should be close to the answer
M
1.3
.
They see that the two lines intersect at
x=
M
1.3
.
Note
: See the
TI
-
83 Plus Guidebook
, for information on the TI
-
83 Plus automatic feature “Intersection,” which is not covered in this
section. This feature is not on the TI
-
73.
Solution Search:
Students write the solution and explain how they found the solution using
graphs and tables for each of the problems below.
Tell students to:
•
Review how to use the graphing features of the calculator to search for a solution.
•
Find the intersection of the lines by tracing the graph. Remind students that the viewing
window must be set appropriately to find the intersection, and finding the exact solution is
not guaranteed; they must combine the two methods to find the solutions.
•
Use number sense to complete the search.
1. p + 3 = 1
when
p =
M
2 2. 3x
−
2 = 1.6
when
x = 1.2
3.
1
2
x +
5
8
=
7
8
when
x =
1
2
4. 4 + 0.5C = 7
when
C = 6