Learn on PengiBig Ideas Math, Advanced 2Chapter 6: Functions

Section 6.1: Relations and Functions

In this Grade 7 lesson from Big Ideas Math Advanced 2, students learn to define relations and functions, represent them using ordered pairs and mapping diagrams, and determine whether a relation qualifies as a function by checking that each input is paired with exactly one output. Through activities involving area, perimeter, circumference, and volume, students practice constructing and interpreting mapping diagrams to describe relationships between two data sets.

Section 1

Introduction to Input-Output Relationships

Property

In many real-world situations, there is a relationship between two quantities where one quantity (the input) determines the value of another quantity (the output). We can identify these input-output relationships by examining how changes in one variable correspond to changes in another variable.

Examples

Section 2

Relation, Domain, and Range

Property

A relation is any set of ordered pairs, (x,y)(x, y). All the xx-values in the ordered pairs together make up the domain. All the yy-values in the ordered pairs together make up the range.
A mapping is sometimes used to show a relation. The arrows show the pairing of the elements of the domain with the elements of the range.

Examples

  • For the relation {(10, A), (20, B), (30, C)}, the domain is {10, 20, 30} and the range is {A, B, C}.
  • In the relation {(apple, red), (banana, yellow), (grape, purple), (lime, green)}, the domain is {apple, banana, grape, lime} and the range is {red, yellow, purple, green}.

Section 3

Spotting Functions in Tables and Mapping Diagrams

Property

Relations can be represented in three equivalent forms: ordered pairs (x, y), tables, and mapping diagrams with arrows.

To be a function, every input must have exactly one arrow pointing away from it (in a diagram) or correspond to exactly one output (in a table). It is completely acceptable for different inputs to share the same output.

Examples

  • Valid Function: A table shows the months of the year (input) and the number of days in that month (output). Multiple months like January and March have the exact same output (31 days), which is perfectly allowed.

Book overview

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Chapter 6: Functions

  1. Lesson 1Current

    Section 6.1: Relations and Functions

  2. Lesson 2

    Section 6.2: Representations of Functions

  3. Lesson 3

    Section 6.3: Linear Functions

  4. Lesson 4

    Lesson 4: Section 6.4: Comparing Linear and Nonlinear Functions

  5. Lesson 5

    Lesson 5: Section 6.5: Analyzing and Sketching Graphs

Lesson overview

Expand to review the lesson summary and core properties.

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Section 1

Introduction to Input-Output Relationships

Property

In many real-world situations, there is a relationship between two quantities where one quantity (the input) determines the value of another quantity (the output). We can identify these input-output relationships by examining how changes in one variable correspond to changes in another variable.

Examples

Section 2

Relation, Domain, and Range

Property

A relation is any set of ordered pairs, (x,y)(x, y). All the xx-values in the ordered pairs together make up the domain. All the yy-values in the ordered pairs together make up the range.
A mapping is sometimes used to show a relation. The arrows show the pairing of the elements of the domain with the elements of the range.

Examples

  • For the relation {(10, A), (20, B), (30, C)}, the domain is {10, 20, 30} and the range is {A, B, C}.
  • In the relation {(apple, red), (banana, yellow), (grape, purple), (lime, green)}, the domain is {apple, banana, grape, lime} and the range is {red, yellow, purple, green}.

Section 3

Spotting Functions in Tables and Mapping Diagrams

Property

Relations can be represented in three equivalent forms: ordered pairs (x, y), tables, and mapping diagrams with arrows.

To be a function, every input must have exactly one arrow pointing away from it (in a diagram) or correspond to exactly one output (in a table). It is completely acceptable for different inputs to share the same output.

Examples

  • Valid Function: A table shows the months of the year (input) and the number of days in that month (output). Multiple months like January and March have the exact same output (31 days), which is perfectly allowed.

Book overview

Jump across lessons in the current chapter without opening the full course modal.

Continue this chapter

Chapter 6: Functions

  1. Lesson 1Current

    Section 6.1: Relations and Functions

  2. Lesson 2

    Section 6.2: Representations of Functions

  3. Lesson 3

    Section 6.3: Linear Functions

  4. Lesson 4

    Lesson 4: Section 6.4: Comparing Linear and Nonlinear Functions

  5. Lesson 5

    Lesson 5: Section 6.5: Analyzing and Sketching Graphs