← Back to Topic 10

Identifying Functions from Graphs: Classroom Packet

Grade 8 Algebra: Identifying Functions from Graphs

Name: ______________________Date: ____________Score: ____ / 8

Level 1

Lines and familiar curves

Directions: Use the vertical line test to decide whether each graph represents a function of x{x}.

  1. 1.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  2. 2.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  3. 3.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  4. 4.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  5. 5.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  6. 6.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  7. 7.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  8. 8.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy

Answer Key

Level 1

  1. 1. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  2. 2. No: fails the vertical line test\text{No: fails the vertical line test}
  3. 3. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  4. 4. No: fails the vertical line test\text{No: fails the vertical line test}
  5. 5. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  6. 6. No: fails the vertical line test\text{No: fails the vertical line test}
  7. 7. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  8. 8. Yes: passes the vertical line test\text{Yes: passes the vertical line test}

Grade 8 Algebra: Identifying Functions from Graphs

Name: ______________________Date: ____________Score: ____ / 8

Level 2

Discrete points

Directions: Use the vertical line test to decide whether each graph represents a function of x{x}.

  1. 1.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  2. 2.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  3. 3.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  4. 4.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  5. 5.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  6. 6.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  7. 7.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  8. 8.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy

Answer Key

Level 2

  1. 1. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  2. 2. No: fails the vertical line test\text{No: fails the vertical line test}
  3. 3. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  4. 4. No: fails the vertical line test\text{No: fails the vertical line test}
  5. 5. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  6. 6. No: fails the vertical line test\text{No: fails the vertical line test}
  7. 7. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  8. 8. Yes: passes the vertical line test\text{Yes: passes the vertical line test}

Grade 8 Algebra: Identifying Functions from Graphs

Name: ______________________Date: ____________Score: ____ / 8

Level 3

Shifted curves and relations

Directions: Use the vertical line test to decide whether each graph represents a function of x{x}.

  1. 1.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  2. 2.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  3. 3.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  4. 4.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  5. 5.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  6. 6.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  7. 7.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy
  8. 8.
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    −5-5
    −4-4
    −3-3
    −2-2
    −1-1
    11
    22
    33
    44
    55
    xx
    yy

Answer Key

Level 3

  1. 1. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  2. 2. No: fails the vertical line test\text{No: fails the vertical line test}
  3. 3. No: fails the vertical line test\text{No: fails the vertical line test}
  4. 4. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  5. 5. No: fails the vertical line test\text{No: fails the vertical line test}
  6. 6. Yes: passes the vertical line test\text{Yes: passes the vertical line test}
  7. 7. No: fails the vertical line test\text{No: fails the vertical line test}
  8. 8. Yes: passes the vertical line test\text{Yes: passes the vertical line test}