Graphs of the Linear Function:
Graphing Calculator TI-84 Plus
Presented by Victor Zinger
Exit
Table of Contents
•
•
•
•
•
•
•
•
•
•
•
•
•
Welcome
TI-84 Plus Keyboard
Dimensions of the screen
Exploring Y-screen and Table of values
Exploring Y-screen and Table of values(continue)
Example # 1
Solving Linear Equations Graphically
Example # 2
Linear Inequalities
Problem Solving Strategy
Applications of Linear Function: Line of the Best Fit
Line of the Best Fit
Thank You!
Welcome
• My name is Victor Zinger. I
am Professor of
Mathematics at the
University of Alaska
Fairbanks. Mathematics is
important for everyone’s
career and success in their
lives. Mathematics is
language for all-let’s make it
understandable!
TI-84 Plus Keyboard
• Lower center (white keys):
Arithmetic Keys
• Lower Right (gray keys):
Basic Operations
• Lower Left (black keys):
Basic Functions
• Top Row: (gray keys):
Display Keys
• Next Three Rows:
Special Program Keys
• Middle Row: (black keys):
Trig. and Inverse Trig. Functions
Dimensions of the screen
Press the WINDOW key (top row) to see
the Window Screen shown to the right:
This shows that the dimensions of the
graphing window are: -4.7 < x < 4.7 and 3.1 < y < 3.1
Also, the tick marks are spaced by 1 unit
on each axis.
Using the ARROW keys to move the
blinking cursor, change the screen
dimensions to: -1 < x < 5 and -2 < y < 10
Exploring Y-screen and Table of values
•Use the MODE key to select the
"Func" mode of function entry.
•Use the Y= key to select (or enter
fresh) for example function: Y2=2x+1
•Press the 2nd key, then the WINDOW
key (= Tblset).
•Edit the Table Setup Window as
shown to the right.
Video clip
Exploring Y-screen and Table of values
Press the 2nd key then the
GRAPH key (= TABLE key) to
see the table of values to the
right. These are the values of the
functions y1=3x*2^(-x) and
y2=2x+1.
Use the Up and Down ARROWS
to scroll through the values.
Press the 2nd key, then the
WINDOW key (= Tblset). Note
that the TblMin value is the the
topmost x-value displayed on the
table.
Edit the Table Setup values to
TblMin=-2 and (delta)Tbl=1.
Press 2nd then GRAPH.
.
Example # 1
Solving a system of linear equations: y  2 x  7
TI-84 Plus:
1. Press "Y="
1
y  x3
2
2. Enter both equations, solved for Y
3. Press "GRAPH"
4. If all intersection points are not visible, press "ZOOM" then 0 or select "0: ZoomFit"
5. Press "2nd" then "TRACE"
6. Press 5 or select "5: intersect"
7. Move the cursor to one of the intersection points. (There may be only one) Each of these
points represents one solution to the system.
8. Press "ENTER" three times
9. The coordinates of the intersection are shown at the bottom of the screen
Solving Linear Equations Graphically
Solve the equation:
10000 = 214.2 (x – 1950) + 2322
STEP 1: Set Y1 equal to the left side
of the equation and set equal to the
right side of the equation.
STEP 2: Graph Y1 and Y2 in the
same viewing rectangle.
STEP 3: Locate any points of
intersection. The x-values of these
points correspond to the solutions to
the equation.
STEP 4: Press 2nd TRACE[CALC], then
press 5 to select intersect.
TI -84 Tutorial
Example # 2
Solve linear inequality
y  3x  3
Instruction: Notice the "shade
below" symbol to the far left of the
Y1.
Again, you must determine whether
to draw a solid or dotted line. This
problem uses a dotted line because
it is strictly "less than" (no "equal
to").
Linear Inequalities
Graph y  2 x  1
Enter 2x + 1 into Y1
Arrow to the far left side of Y1
Press ENTER until the "shade above" symbol is displayed.
Press ZOOM #6 ZStandard (for a 10x10 window)
Graph
y  2 x  1to draw a solid line or a dotted
NOTE: You will have to determine whether
line for y = 2x + 1. This problem uses a solid line because of the "less than
or equal to" sign. The calculator will display a solid line at all times.
Problem Solving Strategy
Check
Solve
Understand
Algebraic
Problem
Write
Equation
Plan
Applications of Linear Function: Line of the
Best Fit
Problem: “Maximum Heart Rate” A person
who is exercising should not exceed his or
her maximum heart rate, which is
determined on the basis of that person’s
sex, age, and resting heart rate. The
following table relates resting heart rate
and maximum heart rate for a 20-year-old
man.
Use a graphing calculator to model the
data with a linear function.
Link to Tutorial
Resting Heart
Rate, H
(In Beats Per
Minute
Maximum Heart
Rate, M
(In Beats Per
Minute
50
166
60
168
70
170
80
172
Line of the Best Fit
Thank You and Good Luck!