Rational and Radical Functions

Students will extend their understanding of inverse functions to functions with a degree higher than 1, and factor and simplify rational expressions to reveal domain restrictions and asymptotes.

Math

Unit 4

11th Grade

Unit Summary


In Unit 4, students will extend their understanding of inverse functions to functions with a degree higher than 1. Alongside this concept, students will factor and simplify rational expressions and functions to reveal domain restrictions and asymptotes. Students will become fluent in operating with rational and radical expressions and use the structure to model contextual situations. In this unit, students will also revisit the concept of an extraneous solution, first introduced in Unit 1, through the solution of radical and rational equations. 

The unit begins with Topic A, where there is a focus on understanding the graphical and algebraic connections between rational and radical expressions, as well as fluently writing these expressions in different forms. In Topic B, students delve deeper into rational equations and functions and identify characteristics such as the $$x$$- and $$y$$-intercepts, asymptotes, and removable discontinuities based on the relationship between the degree of the numerator and denominator of the rational expression. Students will also connect these features with the transformation of the parent function of a rational function. In Topic C, students solve rational and radical equations, identifying extraneous solutions, then modeling and solving equations in situations where rational and radical functions are necessary. Students will connect the domain algebraically with the context and interpret solutions.

Pacing: 20 instructional days (18 lessons, 1 flex day, 1 assessment day)

Assessment


The following assessments accompany Unit 4.

Post-Unit

Use the resources below to assess student understanding of the unit content and action plan for future units.

Unit Prep


Intellectual Prep

Internalization of Standards via the Unit Assessment

  • Take unit assessment. Annotate for: 
    • Standards that each question aligns to
    • Purpose of each question: spiral, foundational, mastery, developing
    • Strategies and representations used in daily lessons
    • Relationship to Essential Understandings of unit 
    • Lesson(s) that assessment points to

Internalization of Trajectory of Unit

  • Read and annotate “Unit Summary."
  • Notice the progression of concepts through the unit using “Unit at a Glance.”
  • Do all target tasks. Annotate the target tasks for: 
    • Essential understandings
    • Connection to assessment questions 

Essential Understandings

  • A rational function is a ratio of polynomial functions. If a rational function does not have a constant in the denominator, the graph of the rational function features asymptotic behavior and can have other features of discontinuity. 
  • Rational and radical equations that have algebraic numerators or denominators operate within the same rules as fractions. 
  • Extraneous solutions may result due to domain restrictions in rational or radical functions. 
  • Rational functions can be used to model situations in which two polynomials or root functions are divided. 

Vocabulary

Vertical and horizontal asymptote Invertible functions
Rational function Zero product property 
Rational expression Asymptotic discontinuities (infinite)
Domain restriction Removable discontinuities
Square root / cube root End behavior
Extraneous solutions Sign chart

Lesson Map


Topic A: Introduction to Rational and Radical Functions and Expressions

Topic B: Features of Rational Functions and Graphing Rational Functions

Topic C: Solve Rational and Radical Equations and Model with Rational Functions

Common Core Standards


Key

Major Cluster

Supporting Cluster

Additional Cluster

Core Standards

Arithmetic with Polynomials and Rational Expressions

Building Functions

Creating Equations

High School — Number and Quantity

Interpreting Functions

Reasoning with Equations and Inequalities

Foundational Standards

Arithmetic with Polynomials and Rational Expressions

Building Functions

Creating Equations

Expressions and Equations

Interpreting Functions

Reasoning with Equations and Inequalities

Seeing Structure in Expressions

Standards for Mathematical Practice

  • CCSS.MATH.PRACTICE.MP1 — Make sense of problems and persevere in solving them.

  • CCSS.MATH.PRACTICE.MP2 — Reason abstractly and quantitatively.

  • CCSS.MATH.PRACTICE.MP3 — Construct viable arguments and critique the reasoning of others.

  • CCSS.MATH.PRACTICE.MP4 — Model with mathematics.

  • CCSS.MATH.PRACTICE.MP5 — Use appropriate tools strategically.

  • CCSS.MATH.PRACTICE.MP6 — Attend to precision.

  • CCSS.MATH.PRACTICE.MP7 — Look for and make use of structure.

  • CCSS.MATH.PRACTICE.MP8 — Look for and express regularity in repeated reasoning.

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New Math Materials Now Live!

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