Polynomials

Students analyze features of polynomials using their equations and graphs, perform arithmetic operations on polynomials, and use polynomial identities to solve problems.

Unit Summary

In Unit 3, Polynomials, students will apply skills from the first two units to develop an understanding of the features of polynomial functions. Analysis of polynomial functions for degree, end behavior, number, and type of solutions builds on the work done in Unit 2; advanced topics that will be applied to future function types. Students will write polynomial functions to reveal features of the functions, find solutions to systems, and apply transformations, building from Units 1 and 2. Students will be introduced to the idea of an “identity” in this unit as well as operate with polynomials. Division of polynomials is introduced in this unit and will be explored through the concepts of remainder theorem as well as a prerequisite to rational functions. 

Unit 3 begins with Topic A, Polynomial Features and Graphs, where students dive into the features of polynomial functions—focusing on end behavior, real and complex roots, where a function is positive or negative, and review of transformations. In this part of the unit, students will focus on looking for structure in equations indicating roots, degree, leading coefficient, etc., and apply this knowledge to graphs, and vice versa. Students will be introduced to new tools, such as sign charts, to aid in the sketch of a polynomial graph.

In Topic B, Operations with Polynomials, students focus on precision of calculations as well as expressing regularity in repeated reasoning with the binomial theorem, the remainder theorem, and various factoring patterns. Students will make connections between Topic A and Topic B by identifying linear factors, number and kind of roots, and end behavior. 

In Topic C, Polynomial Extensions, students will use strategies learned throughout the unit to find the solution to systems of polynomial functions, write polynomial functions, and identify Pythagorean triples. Students will need to identify appropriate “tools” (procedures) that will lead them to the solution of various mathematical problems. 

The features of polynomial functions, such as end behavior and function behavior, and the operations with polynomials, such as factoring and division, will be used in the next unit, Rational Functions. The conceptual knowledge gained in this unit will be essential to fully understanding rational functions.

Assessment

This assessment accompanies Unit 3 and should be given on the suggested assessment day or after completing the unit.

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

?

  1. Polynomials are described by their degree and leading coefficient. By knowing this information, you can describe the end behavior and number of roots, and make predictions about the shape of the graph. 
  2. Solutions of polynomial functions represent the intersection of two polynomial functions or the intersection of the function across the x-axis. The method to finding these intersections include systems of equations, factoring and factoring patterns, quadratic formula, and long division. Solutions to polynomial functions may be either real or complex.
  3. By analyzing the structure of a polynomial function represented as a table, equation, or graph, you can determine efficient methods and procedures to finding solutions, features, and alternative representations of polynomial functions.

Vocabulary

?

polynomials roots/solutions degree
leading coefficient Fundamental Theorem of Algebra difference of two squares
pythagorean triples conjugate polynomial long division
successive differences end behavior complex root/real root
factors remainder theorem difference/sum of two cubes
polynomial identities rate of change  

 

Lesson Map

Topic A: Polynomial Features and Graphs

Topic B: Operations with Polynomials

Topic C: Polynomial Extensions

Common Core Standards

Key: Major Cluster Supporting Cluster Additional Cluster

Core Standards

?

Arithmetic with Polynomials and Rational Expressions
  • A.APR.A.1 — Understand that polynomials form a system analogous to the integers, namely, they are closed under the operations of addition, subtraction, and multiplication; add, subtract, and multiply polynomials.

  • A.APR.B.2 — Know and apply the Remainder Theorem: For a polynomial p(x) and a number a, the remainder on division by x - a is p(a), so p(a) = 0 if and only if (x - a) is a factor of p(x).

  • A.APR.B.3 — Identify zeros of polynomials when suitable factorizations are available, and use the zeros to construct a rough graph of the function defined by the polynomial.

  • A.APR.C.4 — Prove polynomial identities and use them to describe numerical relationships. For example, the polynomial identity (x² + y²)2 = (x² — y²)² + (2xy)² can be used to generate Pythagorean triples.

Building Functions
  • F.BF.A.1.B — Combine standard function types using arithmetic operations. For example, build a function that models the temperature of a cooling body by adding a constant function to a decaying exponential, and relate these functions to the model.

  • F.BF.B.3 — Identify the effect on the graph of replacing f(x) by f(x) + k, k f(x), f(kx), and f(x + k) for specific values of k (both positive and negative); find the value of k given the graphs. Experiment with cases and illustrate an explanation of the effects on the graph using technology. Include recognizing even and odd functions from their graphs and algebraic expressions for them.

Interpreting Functions
  • F.IF.B.4 — For a function that models a relationship between two quantities, interpret key features of graphs and tables in terms of the quantities, and sketch graphs showing key features given a verbal description of the relationship. Key features include: intercepts; intervals where the function is increasing, decreasing, positive, or negative; relative maximums and minimums; symmetries; end behavior; and periodicity. Modeling is best interpreted not as a collection of isolated topics but in relation to other standards. Making mathematical models is a Standard for Mathematical Practice, and specific modeling standards appear throughout the high school standards indicated by a star symbol (★). The star symbol sometimes appears on the heading for a group of standards; in that case, it should be understood to apply to all standards in that group.

  • F.IF.B.6 — Calculate and interpret the average rate of change of a function (presented symbolically or as a table) over a specified interval. Estimate the rate of change from a graph. Modeling is best interpreted not as a collection of isolated topics but in relation to other standards. Making mathematical models is a Standard for Mathematical Practice, and specific modeling standards appear throughout the high school standards indicated by a star symbol (★). The star symbol sometimes appears on the heading for a group of standards; in that case, it should be understood to apply to all standards in that group.

  • F.IF.C.7.C — Graph polynomial functions, identifying zeros when suitable factorizations are available, and showing end behavior.

  • F.IF.C.8.A — Use the process of factoring and completing the square in a quadratic function to show zeros, extreme values, and symmetry of the graph, and interpret these in terms of a context.

  • F.IF.C.9 — Compare properties of two functions each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). For example, given a graph of one quadratic function and an algebraic expression for another, say which has the larger maximum.

Linear, Quadratic, and Exponential Models
  • F.LE.A.3 — Observe using graphs and tables that a quantity increasing exponentially eventually exceeds a quantity increasing linearly, quadratically, or (more generally) as a polynomial function.

Reasoning with Equations and Inequalities
  • A.REI.D.11 — Explain why the x-coordinates of the points where the graphs of the equations y = f(x) and y = g(x) intersect are the solutions of the equation f(x) = g(x); find the solutions approximately, e.g., using technology to graph the functions, make tables of values, or find successive approximations. Include cases where f(x) and/or g(x) are linear, polynomial, rational, absolute value, exponential, and logarithmic functions. Modeling is best interpreted not as a collection of isolated topics but in relation to other standards. Making mathematical models is a Standard for Mathematical Practice, and specific modeling standards appear throughout the high school standards indicated by a star symbol (★). The star symbol sometimes appears on the heading for a group of standards; in that case, it should be understood to apply to all standards in that group.

Seeing Structure in Expressions
  • A.SSE.A.2 — Use the structure of an expression to identify ways to rewrite it. For example, see x4 — y4 as (x²)² — (y²)², thus recognizing it as a difference of squares that can be factored as (x² — y²)(x² + y²).

Foundational Standards

?

Building Functions
  • F.BF.A.1

  • F.BF.B.3

Geometry
  • 8.G.B.7

Interpreting Functions
  • F.IF.A.3

  • F.IF.B.4

  • F.IF.C.7.A

  • F.IF.C.8.A

  • F.IF.C.9

Reasoning with Equations and Inequalities
  • A.REI.A.1

  • A.REI.B.3

  • A.REI.D.10

Seeing Structure in Expressions
  • A.SSE.A.2

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.