Name
T E K S A.2.A
Date
LESSON
9-1
Class
Practice B
Identifying Quadratic Functions
Tell whether each function is quadratic. Explain.
2. 3x ⫹ 2y ⫽ 8
1. 0, 6 , 1, 12 , 2, 20 , 3, 30 Use a table of values to graph each quadratic function.
1x 2
4. y ⫽ 2x 2 ⫺ 3
3. y ⫽ ⫺__
Y
2
x
y
x
Y
y
X
X
Tell whether the graph of each quadratic function opens upward or
downward. Explain.
2
5. y ⫽ ⫺3x ⫹ 5
6. ⫺x 2 ⫹ y ⫽ 8
For each parabola, a) identify the vertex; b) give the minimum or
maximum value of the function; c) find the domain and range.
Y
7.
8.
Y
a.
a.
b.
b.
c.
c.
a107c09-1_pr_TX.indd 60
X
X
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
60
Holt Algebra 1
3/30/06 3:00:51 PM
Name
T E K S A.2.A
Date
LESSON
9-1
Class
Practice B
Identifying Quadratic Functions
Tell whether each function is quadratic. Explain.
2. 3x ⫹ 2y ⫽ 8
1. 0, 6 , 1, 12 , 2, 20 , 3, 30 yes
no
it cannot be written in the form
2
y ⫽ ax ⫹ bx ⫹ c.
the second differences are constant.
Use a table of values to graph each quadratic function.
1x 2
4. y ⫽ 2x 2 ⫺ 3
3. y ⫽ ⫺__
Y
2
x
y
x
Y
y
X
X
Tell whether the graph of each quadratic function opens upward or
downward. Explain.
2
5. y ⫽ ⫺3x ⫹ 5
6. ⫺x 2 ⫹ y ⫽ 8
downward, a ⫽ ⫺3, a ⬍ 0
upward, a ⫽ 1, a ⬎ 0
For each parabola, a) identify the vertex; b) give the minimum or
maximum value of the function; c) find the domain and range.
Y
7.
8.
Y
X
X
a.
⫺2, 6 a.
3, ⫺3 b.
maximum: 6
b.
minimum: ⫺3
c.
D: all real numbers; R: y ⱕ 6
c.
D: all real numbers; R: y ⱖ ⫺3
Copyright © by Holt, Rinehart and Winston.
All rights reserved.
a107c09-1_pr_TX.indd 60
60
Holt Algebra 1
3/30/06 3:00:51 PM