options: Rewrite rational expressions.

Understand the relationship between zeros and factors of polynomials.

Represent and analyze quantitative relationships between dependent and independent variables.

Gain familiarity with factors and multiples.

Represent and solve equations and inequalities graphically.

Solve equations and inequalities in one variable.

Add and subtract within 20.

Use polynomial identities to solve problems.

Understand solving equations as a process of reasoning and explain the reasoning.

Interpret the structure of expressions.

Analyze patterns and relationships.

Represent and solve problems involving addition and subtraction.

Multiply and divide within 100.

Work with addition and subtraction equations.

Create equations that describe numbers or relationships

Understand properties of multiplication and the relationship between multiplication and division.

Use properties of operations to generate equivalent expressions.

Represent and solve problems involving multiplication and division.

Understand and apply properties of operations and the relationship between addition and subtraction.

Work with equal groups of objects to gain foundations for multiplication.

Generate and analyze patterns.

Solve real-life and mathematical problems using numerical and algebraic expressions and equations.

Perform arithmetic operations on polynomials.

Write and interpret numerical expressions.

Reason about and solve one-variable equations and inequalities.

Work with radicals and integer exponents.

Solve problems involving the four operations, and identify and explain patterns in arithmetic.

Understand the connections between proportional relationships, lines, and linear equations.

Use the four operations with whole numbers to solve problems.

Understand addition as putting together and adding to, and understand subtraction as taking apart and taking from.

Write expressions in equivalent forms to solve problems.

Analyze and solve linear equations and pairs of simultaneous linear equations.

Apply and extend previous understandings of arithmetic to algebraic expressions.

Solve systems of equations.
problem_activity: Activity
The goal of this activity is for students to reason about what horizontal intercepts a graph of a polynomial must have based on the structure of the factored form of the polynomial (MP7). Students begin by considering a polynomial equation and graph and reasoning about why the graph window is insufficient since it only shows two out of three intercepts. Students then consider the horizontal intercepts of a different polynomial through the lens of selecting an appropriate viewing window before checking with graphing technology.
Launch
Provide access to devices that can run Desmos or other graphing technology.
Reading, Conversing, Writing: MLR5 Co-Craft Questions.
To help students consider the graph window of a polynomial, start by only displaying Mai’s graph and comment. Give students 1–2 minutes to write their own mathematical questions about the situation. Invite students to compare their questions before revealing the activity’s questions. Listen for and amplify any questions involving the terms “parabola” or “quadratic,” along with any questions about the scale on the axes. This will help students create questions about Mai’s statement and graph as they explore an appropriate graph window.
Design Principle(s): Maximize meta-awareness; Cultivate conversation
Engagement: Develop Effort and Persistence.
Break the class into small discussion groups and then invite a representative from each group to report back to the whole class. Ask that each discussion group member is equally prepared to report back to the whole group. As students work, encourage groups to use peer supports to ensure all group members are prepared to report out if selected.
Supports accessibility for: Language; Social-emotional skills; Attention
Student Facing
Mai graphs the function
\(p\)
given by
\(p(x)=(x+1)(x-2)(x+15)\)
and sees this graph.
[IMG]
She says, “This graph looks like a parabola, so it must be a quadratic.”
Is Mai correct? Use graphing technology to check.
Explain how you could select a viewing window before graphing an expression like
\(p(x)\)
that would show the main features of a graph.
Using your explanation, what viewing window would you choose for graphing
\(f(x)=(x+1)(x-1)(x-2)(x-28)\)
?
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Student Facing
Are you ready for more?
Select some different windows for graphing the function
\(q(x) = 23(x-53)(x-18)(x+111)\)
. What is challenging about graphing this function?
Student Response
Teachers with a valid work email address can
click here to register or sign in
for free access to Extension Student Response.
Anticipated Misconceptions
If students have trouble deciding what the constant term of
\(f(x)\)
is, remind them that it can be found quickly by multiplying the constant terms of each linear factor. Students can use the distributive property to understand why this is true.
Activity Synthesis
Select students to share how they selected a viewing window for
\(f(x)=(x+1)(x-1)(x-2)(x-28)\)
. In particular, ask students to state what structure in the factored form they focused on in order to select their window size.
If students question whether we can really be sure we’re seeing all the horizontal intercepts, tell them that in future lessons, they will learn more about what functions are doing to the far left and right of a graph and how we can be sure there are no other horizontal intercepts outside our viewing window. Later in this unit, they will see that all zeros of a function correspond to factors of the function.


correct_option_index: 9