Relations and Functions

How do we know if a relation is a function?

• The y-value cannot repeat
• The x-value must equal zero
• The y-value must equal zero
• The x-value cannot repeat

Tags

CCSS.8.F.A.1

What is the domain and range of this relation? Is it a function?

• Domain: {15⁄4, 17⁄4, 15, 17}
  Range: {15⁄4, 17⁄4, 15, 17}
  Function: Yes
• Domain: {15⁄4, 15, 17⁄4, 17}
  Range: {15⁄4, 15, 17⁄4, 17}
  Function: Yes
• Domain: {17, 15, 17⁄4, 15⁄4}
  Range: {17, 15, 17⁄4, 15⁄4}
• Domain: {15⁄4, 17⁄4, 15, 17}
  Range: {15⁄4, 17⁄4, 15, 17}
  Function: No

Tags

CCSS.8.F.A.1

What is the domain and range of this relation? Is it a function?

• Domain: {-2, -1, 1, 3}
  Range: {-2, 0, 1, 3}
  Function: Yes
• Domain: {-2, -1, 1, 3}
  Range: {-2, 0, 1, 3}
  Function: No
• Domain: {-2, -1,1, 1, 3}
  Range: {-2, -2, 0, 1, 3}
  Function: No
• Domain: {-2, 0, 1, 3}
  Range: {-2, -1, 1, 3}
  Function: No

Tags

CCSS.8.F.A.1

What is the domain and range of this relation? Is it a function?

• Domain: -2 < y < 2
  Range: -2 < x < 2
  Function: No
• Domain: -2 ≤ x ≤ 2
  Range: -2 ≤ y ≤ 2
  Function: No
• Domain: -2 < x < 2
  Range: -2 < y < 2
  Function: No
• Domain: -2 ≤ x ≤ 2
  Range: -2 ≤ y ≤ 2
  Function: Yes

How do we know if a graph is NOT a function?

• It will pass the VLT
• A y-value will repeat
• It will fail the VLT
• An x-value will repeat