Try our Free Online Math Solver!

Graphing Quadratics Using the TI83
Teacher’s Notes:
Solutions to Developmental Activity:
1.
Equation of parabola  Vertex  x intercept (s)  yintercept  Axis of symmetry 
y = x^{2}  (0, 0)  (0, 0)  (0, 0)  x = 0 
y = x^{2} + 2  (0, 2)  None  (0, 2)  x = 0 
y = x^{2} – 2  (0, 2)  1.41 and –1.41  (0, 2)  x = 0 
y = x^{2} + x  (.5, .25)  0 and –1  (0, 0)  x = .5 
y = x^{2} + 5x  (2.5, 6.25)  0 and –5  (0, 0)  x = 2.5 
y = x^{2} – 5x  (2.5, 6.25)  5 and 0  (0, 0)  x = 2.5 
y = x^{2} – 3x +2  (1.5, .25)  2 and 1  (0, 2)  x = 1.5 
y = x^{2} – 4x  (2,4)  0 and –4  (0, 0)  x = 2 
y = x^{2} – 3x – 4  (1.5, 6.25)  4 and –1  (0, 4)  x = 1.5 
2. Answers will vary.
3.
a: Changing a will make the parabola more narrow or wide. Changing the sign
of a
will make the graph open up or down.
b: Changing b will move the vertex of the parabola .
c: Changing c will change the yintercept.
Ticket Out:
Answers will be collected as the students exit the room. The information will be
used to
assess the students understanding of the lesson covered.
Solutions to Homework:
5. True
7b.
7c. (1, 4); minimum
7d. –3
9a. (3,1)
9b. x = 3
12a. (4, 35)
12b. x = 4
12c. 19, 5, 13
Exploring y = ax^{2} + bx + c
Name: ____________________
Period: _____
Directions: Log on to the computer and go to the following website:
Set the graph tool so that a = 1, b = 0, and c = 0. Click
in the box that says show
vertex/ intercept data .
1. Complete the table below:
Equation of parabola  Vertex  xintercept  yintercept  Axis of symmetry 
y = x^{2}  
y = x^{2} + 2  
y = x^{2} – 2  
y = x^{2} + x  
y = x^{2} + 5x  
y = x^{2} – 5x  
y = x^{2} – 3x +2  
(2,4)  0 and –4  (0, 0)  
(1.5, 6.25)  4 and –1  (0, 4) 
2. Was it difficult to graph the parabola given only the
vertex and the intercepts?
3. For each letter a, b, and c give a general rule for what happens when you
change only
that value.
a:
b:
c:
Day 3
Lesson Plan:
Objectives:
1. Students will be able to graph and interpret equations of the form y = ax^{2} +
bx + c.
Standards:
• NCTM Standards covered: Algebra , Representation
• NYS Standards covered: 7A, 7C
Materials:
• Graphing calculators
• Lesson Master 93B and overhead transparency of worksheet
• Overhead with calculator unit
Opening Activity:
The students will answer the following questions upon entering the room.
Tell what you know about a, b, or c in the equation y = ax^{2} + bx + c if
1. its vertex is its minimum point
2. the yaxis is the axis of symmetry of the graph
3. The point (0, 6) is on the graph.
Developmental Activity:
The students will work with a partner to complete Lesson Master 93B. The
students will
then be selected to present their answers to the class using the overhead
calculator and the
board.
Ticket Out:
Students will have the last 5 minutes of class to respond to the following
question, also to
address any concerns they had with the lesson.
When graphing on a TI83 how important is it to select the correct window size?
Homework:
Read pgs. 562 – 564, complete pg. 565 # 7 –10.
Teacher’s Notes:
Solutions to Opening Activity:
1. The value of a must be greater than 0.
2. b = 0
3. c = 6
Solutions to Developmental Activity:
1.
a. 5
b. –4
c. x = 5
2a.
2b. They will all open down and have the yaxis as their
axis of symmetry. Their
vertices are at different points , and their graphs appear to get narrower.
2c. It opens down and has the yaxis as its axis of symmetry. The vertex is at
(0, 10). It
is quite narrow.
6
a. (10, 144)
b. x = 10
c. –14.7 and –5.3
7b. (1, 2), (3, 10)
Solutions to Homework:
9a.
9b. (9, 12)
9c. x = 9
9d. –12 and –7
10a. 3
10b. 16
Prev  Next 