Standards - Mathematics

MA19.8A.4

Interpret linear, quadratic, and exponential expressions in terms of a context by viewing one or more of their parts as a single entity. [Algebra I with Probability, 4]

COS Examples

Example: Interpret the accrued amount of investment $P(1 + r)^t$, where $P$ is the principal and $r$ is the interest rate, as the product of $P$ and a factor depending on time $t$.

Unpacked Content

Knowledge

Students know:
  • Interpretations of parts of algebraic expressions such as terms, factors, and coefficients.

Skills

Students are able to:
  • Produce mathematical expressions that model given contexts.
  • Provide a context that a given mathematical expression accurately fits.
  • Explain the reasoning for selecting a particular algebraic expression by connecting the quantities in the expression to the physical situation that produced them.

Understanding

Students understand that:
  • Physical situations can be represented by algebraic expressions which combine numbers from the context, variables representing unknown quantities, and operations indicated by the context.
  • Different, but equivalent, algebraic expressions can be formed by approaching the context from a different perspective.

Vocabulary

  • Expression
  • Terms
  • Coefficient
  • Factors
  • linear expression
  • quadratic expression
  • Exponential expression

MA19.8A.5

Use the structure of an expression to identify ways to rewrite it. [Algebra I with Probability, 5]

COS Examples

Example: See $x^4 - y^4$ as $(x^2)^2 - (y^2)^2$, thus recognizing it as a difference of squares that can be factored as $(x^2 - y^2)(x^2 + y^2)$.

Unpacked Content

Knowledge

Students know:
  • Properties of operations (including those in Appendix D, Table 1),
  • When one form of an algebraic expression is more useful than an equivalent form of that same expression.

Skills

Students are able to:
  • -Use algebraic properties to produce equivalent forms of the same expression by recognizing underlying mathematical structures.
    For example, 3(x-5) = 3x-15 and 2a+12 = 2(a+6) or3a-a+10+2and x2-2x-15 = (x-5) (x+3).

Understanding

Students understand that:
  • Generating simpler, but equivalent, algebraic expressions facilitates the investigation of more complex algebraic expressions.

Vocabulary

  • like terms
  • Expression
  • Factor
  • properties of operations (Appendix D, Table 1)
  • Difference of squares

MA19.8A.6

Choose and produce an equivalent form of an expression to reveal and explain properties of the quantity represented by the expression.

Unpacked Content

Knowledge

Students know:
  • The vertex form of a quadratic expression asf (x) = a(x
  • h)2 + k, where (h, k) is the vertex of the parabola.
  • Techniques for generating equivalent forms of an algebraic expression including factoring and completing the square for quadratic expressions and using properties of exponents,
  • When one form of an algebraic expression is more useful than an equivalent form of that same expression to solve a given problem.

Skills

Students are able to:
  • Use algebraic properties including properties of exponents to produce equivalent forms of the same expression by recognizing underlying mathematical structures,
  • Factor quadratic expressions with leading coefficient of one
  • Complete the square in quadratic expressions.

Understanding

Students understand that:
  • An expression may be written in various equivalent forms.
  • Some forms of the expression are more beneficial for revealing key properties of the function.

Vocabulary

  • Function
  • zero of a function
  • Roots
  • parabola
  • vertex form of a quadratic expression
  • Minimum and maximum value
  • Axis of symmetry
  • Completing the square
  • Exponential growth and decay

MA19.8A.6b

Use the vertex form of a quadratic expression to reveal the maximum or minimum value and the axis of symmetry of the function it defines; complete the square to find the vertex form of quadratics with a leading coefficient of one.

MA19.8A.6c

Use the properties of exponents to transform expressions for exponential functions. [Algebra I with Probability, 6]

COS Examples

Example: Identify percent rate of change in functions such as $y = (1.02)^t$, $y = (0.97)^t$, $y = (1.01)^{12t}$, or $y = (1.2)^{t/10}$, and classify them as representing exponential growth or decay.

MA19.8A.7

Add, subtract, and multiply polynomials, showing that polynomials form a system analogous to the integers, namely, they are closed under the operations of addition, subtraction, and multiplication. [Algebra I with Probability, 7]

Unpacked Content

Knowledge

Students know:
  • Corresponding rules of arithmetic of integers, specifically what it means for the integers to be closed under addition, subtraction, and multiplication, and not under division,
  • Procedures for performing addition, subtraction, and multiplication on polynomials.

Skills

Students are able to:
  • Communicate the connection between the rules for arithmetic on integers and the corresponding rules for arithmetic on polynomials,
  • Accurately perform combinations of operations on various polynomials.

Understanding

Students understand that:
  • There is an operational connection between the arithmetic on integers and the arithmetic on polynomials.

Vocabulary

  • Polynomials
  • Closure
  • Analogous system

MA19.8A.8

Analyze the relationship (increasing or decreasing, linear or non-linear) between two quantities represented in a graph. [Grade 8, 17]

Unpacked Content

Knowledge

Students know:
  • Characteristics of representations for functions in graphic form.

Skills

Students are able to:
  • Use mathematical vocabulary and understanding of functions to describe relationships between two quantities.

Understanding

Students understand that:
  • Functions can be represented in a variety of ways, each of which provides unique perspectives of the relationship between the variables.
  • Graphs of functions are useful to compare characteristics of different relationships.

Vocabulary

  • Increasing
  • Decreasing
  • linear
  • non-linear

MA19.8A.9a

Explain that the solution(s) of systems of two linear equations in two variables corresponds to points of intersection on their graphs because points of intersection satisfy both equations simultaneously.

MA19.8A.9b

Interpret and justify the results of systems of two linear equations in two variables (one solution, no solution, or infinitely many solutions) when applied to real-world and mathematical problems. [Grade 8, 12]

MA19.8A.10

Explain why extraneous solutions to an equation involving absolute values may arise and how to check to be sure that a candidate solution satisfies an equation. [Algebra I with Probability, 8]

Unpacked Content

Knowledge

Students know:
  • Absolute value cannot equal a negative number.
  • Substitution techniques to determine true or false statements.

Skills

Students are able to:
  • solve absolute value equations.
  • Substitute possible solutions into original equations to determine if it is in fact a solution or not.

Understanding

Students understand that:
  • That not all solutions generated algebraically actually satisfy the original absolute value equation.

Vocabulary

  • Extraneous solution
  • Absolute value

MA19.8A.11

Select an appropriate method to solve a quadratic equation in one variable.

Unpacked Content

Knowledge

Students know:
  • Any real number has two square roots, that is, if a is the square root of a real number then so is -a.
  • The method for completing the square.
  • A quadratic equation in standard form (ax2+bx+c=0) has real roots when b2-4ac is greater than or equal to zero and complex roots when b2-4ac is less than zero.

Skills

Students are able to:
  • Take the square root of both sides of an equation.
  • Factor quadratic expressions in the form x2+bx+c where the leading coefficient is one.
  • Use the factored form to find zeros of the function.
  • Complete the square.
  • Use the quadratic formula to find solutions to quadratic equations.
  • Manipulate equations to rewrite them into other forms.

Understanding

Students understand that:
  • Solutions to a quadratic equation must make the original equation true and this should be verified.
  • When the quadratic equation is derived from a contextual situation, proposed solutions to the quadratic equation should be verified within the context given, as well as mathematically.
  • Different procedures for solving quadratic equations are necessary under different conditions.
  • If ab=0, then at least one of a or b must be zero (a=0 or b=0) and this is then used to produce the two solutions to the quadratic equation.
  • Whether the roots of a quadratic equation are real or complex is determined by the coefficients of the quadratic equation in standard form (ax2+bx+c=0).

Vocabulary

  • quadratic equation
  • Square root
  • Factoring
  • Completing the square
  • quadratic formula
  • Derive
  • Real numbers
  • Imaginary numbers
  • Complex numbers

MA19.8A.11a

Use the method of completing the square to transform any quadratic equation in $x$ into an equation of the form $(x - p)^2 = q$ that has the same solutions. Explain how the quadratic formula is derived from this form.

MA19.8A.11b

Solve quadratic equations by inspection (such as $x^2 = 49$), taking square roots, completing the square, the quadratic formula, and factoring, as appropriate to the initial form of the equation, and recognize that some solutions may not be real. [Algebra I with Probability, 9]

MA19.8A.12

Select an appropriate method to solve a system of two linear equations in two variables.

Unpacked Content

Knowledge

Students know:
  • Algebraic techniques for manipulating and solving equations.

Skills

Students are able to:
  • graph a system of linear equations.
  • Generate a table from an equation.
  • Find the solution to a system by graphing, completing a table, substitution, and elimination.
  • Justify which method they used.

Understanding

Students understand that:
  • When the properties of operations and equality are applied to systems of equations, the resulting equations have the same solution as the original.

Vocabulary

  • Elimination
  • Substitution
  • Graph
  • Table
  • Solution to a system of linear equations

MA19.8A.12a

Solve a system of two equations in two variables by using linear combinations; contrast situations in which use of linear combinations is more efficient with those in which substitution is more efficient.

MA19.8A.13

Create equations and inequalities in one variable and use them to solve problems in context, either exactly or approximately. Extend from contexts arising from linear functions to those involving quadratic, exponential, and absolute value functions. [Algebra I with Probability, 11]

Unpacked Content

Knowledge

Students know:
  • When the situation presented in a contextual problem is most accurately modeled by a linear, quadratic, exponential, or absolute value relationship.

Skills

Students are able to:
  • Write equations or inequalities in one variable that accurately model contextual situations.
  • Solve equations and inequalities.

Understanding

Students understand that:
  • Features of a contextual problem can be used to create a mathematical model for that problem.

Vocabulary

  • Inequality
  • Variable
  • Solution set
  • Linear relationship-Quadratic relationship
  • Exponential relationship
  • Absolute value

MA19.8A.14

Create equations in two or more variables to represent relationships between quantities in context; graph equations on coordinate axes with labels and scales and use them to make predictions. Limit to contexts arising from linear, quadratic, exponential, absolute value, and linear piecewise functions. [Algebra I with Probability, 12]

Unpacked Content

Knowledge

Students know:
  • When the situation presented in a contextual problem is most accurately modeled by a linear, quadratic, exponential, absolute value or linear piecewise function.
  • How to graph equations on a coordinate plane.

Skills

Students are able to:
  • Write equations with two or more variables.
  • Graph equations on a coordinate plane with appropriate scales and labels.
  • Make predictions based on the graph.

Understanding

Students understand that:
  • There are relationships among features of a contextual problem, a created mathematical model for that problem, and a graph of that relationship.
  • Models can be used to make predictions.

Vocabulary

  • Linear
  • Quadratic
  • Exponential
  • Absolute Value
  • Linear Piecewise Function
  • x and y axes

MA19.8A.15

Represent constraints by equations and/or inequalities, and solve systems of equations and/or inequalities, interpreting solutions as viable or nonviable options in a modeling context. Limit to contexts arising from linear, quadratic, exponential, absolute value, and linear piecewise functions. [Algebra I with Probability, 13]

Unpacked Content

Knowledge

Students know:
  • When a particular system of two variable equations or inequalities accurately models the situation presented in a contextual problem,
  • Which points in the solution of a system of linear inequalities need to be tested to maximize or minimize the variable of interest.

Skills

Students are able to:
  • Graph equations and inequalities involving two variables on coordinate axes.
  • Identify the region that satisfies both inequalities in a system.
  • Identify the point(s) that maximizes or minimizes the variable of interest in a system of inequalities.
  • Test a mathematical model using equations, inequalities, or a system against the constraints in the context and interpret the solution in this context.

Understanding

Students understand that:
  • A symbolic representation of relevant features of a real-world problem can provide for resolution of the problem and interpretation of the situation and solution.
  • Representing a physical situation with a mathematical model requires consideration of the accuracy and limitations of the model.

Vocabulary

  • Constraints
  • System of equations
  • System of inequalities
  • Solutions
  • Feasible region
  • viable and non
  • viable options
  • linear
  • quadratic
  • Exponential
  • Absolute value
  • linear piecewise
  • Profit
  • Boundary
  • Closed half plane
  • Open half plane
  • Half plane
  • Consistent
  • Inconsistent
  • Dependent
  • Independent
  • Region

MA19.8A.16

Define a function as a mapping from one set (called the domain) to another set (called the range) that assigns to each element of the domain exactly one element of the range. [Grade 8, 13, edited for added content]

Unpacked Content

Knowledge

Students know:
  • Distinguishing characteristics of functions,
  • Conventions of function notation,
  • Techniques for graphing functions,
  • Techniques for determining the domain of a function from its context.

Skills

Students are able to:
  • Accurately graph functions when given function notation.
  • Accurately evaluate function equations given values in the domain.
  • Interpret the domain from the context,
  • Produce a graph of a function based on the context given.

Understanding

Students understand that:
  • Functions are relationships between two variables that have a unique characteristic: that for each input there exists exactly one output.
  • Function notation is useful to see the relationship between two variables when the unique output for each input relation is satisfied.
  • Different contexts produce different domains and graphs.
  • Function notation in itself may produce graph points which should not be in the graph as the domain is limited by the context.

Vocabulary

  • Function
  • Relation
  • Mapping
  • Domain
  • Range
  • Functional notation f(x)
  • Element
  • Input
  • output
  • Quantitative relationship

MA19.8A.16a

Use function notation, evaluate functions for inputs in their domains, and interpret statements that use function notation in terms of a context. [Grade 8, 14, edited for added content]

Note: If $f$ is a function and $x$ is an element of its domain, then $f(x)$ denotes the output of $f$ corresponding to the input $x$.

MA19.8A.16b

Relate the domain of a function to its graph and, where applicable, to the quantitative relationship it describes. Limit to linear, quadratic, exponential, and absolute value functions. [Algebra I with Probability, 15]

MA19.8A.17

Given a relation defined by an equation in two variables, identify the graph of the relation as the set of all its solutions plotted in the coordinate plane. [Algebra I with Probability, 14]

Note: The graph of a relation often forms a curve (which could be a line).

Unpacked Content

Knowledge

Students know:
  • Appropriate methods to find ordered pairs that satisfy an equation,
  • Techniques to graph the collection of ordered pairs to form a curve.

Skills

Students are able to:
  • Accurately find ordered pairs that satisfy the equation.
  • Accurately graph the ordered pairs and form a curve.

Understanding

Students understand that:
  • An equation in two variables has an infinite number of solutions (ordered pairs that make the equation true), and those solutions can be represented by the graph of a curve.

Vocabulary

  • Relation
  • Curve (which could be a line)
  • Graphically Finite solutions
  • Infinite solutions

MA19.8A.18

Compare and contrast relations and functions represented by equations, graphs, or tables that show related values; determine whether a relation is a function. Identify that a function $f$ is a special kind of relation defined by the equation $y = f(x)$. [Algebra I with Probability, 16]

Unpacked Content

Knowledge

Students know:
  • In graphing functions the ordered pairs are (x,f(x)) and the graph is y = f(x).
  • Techniques for graphing functions.
  • Techniques to find key features of functions when presented in different ways.
  • Techniques to convert a function to a different form (algebraically, graphically, numerically in tables, or by verbal descriptions).
  • The vertical line test can be used to determine if a graph is a function.
  • A function is a special kind of relation.

Skills

Students are able to:
  • Accurately determine which key features are most appropriate for comparing functions.
  • Manipulate functions algebraically to reveal key functions.
  • Convert a function to a different form (algebraically, graphically, numerically in tables, or by verbal descriptions) for the purpose of comparing it to another function.

Understanding

Students understand that:
  • Functions can be written in different but equivalent ways (algebraically, graphically, numerically in tables, or by verbal descriptions).
  • Different representations of functions may aid in comparing key features of the functions.

Vocabulary

  • Function
  • Relation
  • vertical line test

MA19.8A.19

Combine different types of standard functions to write, evaluate, and interpret functions in context. Limit to linear, quadratic, exponential, and absolute value functions.

Unpacked Content

Knowledge

Students know:
  • Techniques for expressing functional relationships between two quantities.
  • Techniques to combine functions using arithmetic operations.

Skills

Students are able to:
  • Accurately develop a model that shows the functional relationship between two quantities.
  • Accurately create a new function through arithmetic operations of other functions.
  • Present an argument to show how the function models the relationship between the quantities.

Understanding

Students understand that:
  • Relationships can be modeled by several methods.
  • Arithmetic combinations of functions may be used to improve the fit of a model.

Vocabulary

  • Function composition

MA19.8A.19a

Use arithmetic operations to combine different types of standard functions to write and evaluate functions.

COS Examples

Example: Given two functions, one representing flow rate of water and the other representing evaporation of that water, combine the two functions to determine the amount of water in the container at a given time.

MA19.8A.19b

Use function composition to combine different types of standard functions to write and evaluate functions. [Algebra I with Probability, 17]

COS Examples

Example: Given the following relationships, determine what the expression $S(T(t))$ represents.

MA19.8A.20

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 $f(x) = g(x)$.

Unpacked Content

Knowledge

Students know:
  • Defining characteristics of linear, quadratic, absolute value, and exponential graphs.
  • Methods to use technology, tables, and successive approximations to produce graphs and tables.

Skills

Students are able to:
  • Determine a solution or solutions of a system of two functions.
  • Accurately use technology to produce graphs and tables for linear, quadratic, absolute value, and exponential functions.
  • Accurately use technology to approximate solutions on graphs.

Understanding

Students understand that:
  • When two functions are equal, the x coordinate(s) of the intersection of those functions is the value that produces the same output (y-value) for both functions.
  • Technology is useful to quickly and accurately determine solutions and produce graphs of functions.

Vocabulary

  • Functions
  • Successive approximations
  • Linear functions
  • Quadratic functions
  • Absolute value functions
  • Exponential functions
  • Intersection point(s)

MA19.8A.20a

Find the approximate solutions of an equation graphically, using tables of values, or finding successive approximations, using technology where appropriate. [Algebra I with Probability, 19]

Note: Include cases where $f(x)$ is linear, quadratic, exponential, or absolute value functions and $g(x)$ is constant or linear.

MA19.8A.21

Graph the solutions to a linear inequality in two variables as a half-plane (excluding the boundary in the case of a strict inequality), and graph the solution set to a system of linear inequalities in two variables as the intersection of the corresponding half-planes, using technology where appropriate. [Algebra I with Probability, 20]

Unpacked Content

Knowledge

Students know:
  • When to include and exclude the boundary of linear inequalities.
  • Techniques to graph the boundaries of linear inequalities.
  • Methods to find solution regions of a linear inequality and systems of linear inequalities.

Skills

Students are able to:
  • Accurately graph a linear inequality and identify values that make the inequality true (solutions).
  • Find the intersection of multiple linear inequalities to solve a system.
  • Use technology to graph inequalities and systems of inequalities.

Understanding

Students understand that:
  • Solutions to a linear inequality result in the graph of a half-plane.
  • Solutions to a system of linear inequalities are the intersection of the solutions of each inequality in the system.

Vocabulary

  • Half-planes
  • System of linear inequalities
  • Boundaries
  • Closed half-plane
  • Open half-plane

MA19.8A.22

Solve systems consisting of linear and/or quadratic equations in two variables graphically, using technology where appropriate. [Algebra I with Probability, 18]

Unpacked Content

Knowledge

Students know:
  • The conditions under which a linear equation and a quadratic equation have 0, 1, or 2 solutions.
  • Techniques for producing and interpreting graphs of linear and quadratic equations.
  • Appropriate use of properties of equality.

Skills

Students are able to:
  • Graph linear and quadratic equations precisely and interpret the results.
  • Use technology to graph systems of equations.

Understanding

Students understand that:
  • Solutions of a system of equations is the set of all ordered pairs that make both equations true simultaneously.
  • A system consisting of a linear equation and a quadratic equation will have 0, 1, or 2 solutions.

Vocabulary

  • Solving systems of equations
  • System of equations
  • Cartesian plane
  • Substitution

MA19.8A.23

Compare properties of two functions, each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). Include linear, quadratic, exponential, absolute value, and linear piecewise. [Algebra I with Probability, 21, edited]

Unpacked Content

Knowledge

Students know:
  • Techniques to find key features of functions when presented in different ways.
  • Techniques to convert a function to a different form (algebraically, graphically, numerically in tables, or by verbal descriptions).
  • Characteristics of linear and nonlinear functions.

Skills

Students are able to:
  • Accurately determine which key features are most appropriate for comparing functions.
  • Manipulate functions algebraically to reveal key functions.
  • Convert a function to a different form (algebraically, graphically, numerically in tables, or by verbal descriptions) for the purpose of comparing it to another function.
  • Compare functions based on their properties.

Understanding

Students understand that:
  • Functions can be written in different but equivalent ways (algebraically, graphically, numerically in tables, or by verbal descriptions).
  • Different representations of functions may aid in comparing key features of the functions.
  • Functions are relationships between two variables that have a unique characteristic, that being, for each input there exists exactly one output.
  • Functions can be represented in a variety of ways (graphs, tables, and equations), each of which provides unique perspectives of the relationship between the variables.
  • Linear functions have a defining characteristic of a unit rate or slope that other nonlinear functions do not have.

Vocabulary

  • Linear function
  • Exponential function
  • Quadratic function
  • Absolute value function
  • Linear Piecewise function
  • non-linear functions

MA19.8A.24

Define sequences as functions, including recursive definitions, whose domain is a subset of the integers.

Unpacked Content

Knowledge

Students know:
  • Distinguishing characteristics of a function.
  • Distinguishing characteristics of function notation.
  • Distinguishing characteristics of generating sequences.

Skills

Students are able to:
  • Use the properties of operations and equality and knowledge of recursive functions to justify that an explicit formula that models a sequence is equivalent to a recursive model.

Understanding

Students understand that:
  • Each term in the domain of a sequence defined as a function is unique and consecutive.

Vocabulary

  • Sequence
  • Recursively
  • Domain
  • Arithmetic sequence
  • Geometric sequence
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