3 Define the imaginary number i such that i2 = -1.
AI.AF Algebra and Functions
Focus 1: Algebra
Expressions can be rewritten in equivalent forms by using algebraic properties, including properties of addition, multiplication, and exponentiation, to make different characteristics or features visible.
4 Interpret linear, quadratic, and exponential expressions in terms of a context by viewing one or more of their parts as a single entity.
5 Use the structure of an expression to identify ways to rewrite it.
6.b 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.
Finding solutions to an equation, inequality, or system of equations or inequalities requires the checking of candidate solutions, whether generated analytically or graphically, to ensure that solutions are found and that those found are not extraneous.
8 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.
The structure of an equation or inequality (including, but not limited to, one-variable linear and quadratic equations, inequalities, and systems of linear equations in two variables) can be purposefully analyzed (with and without technology) to determine an efficient strategy to find a solution, if one exists, and then to justify the solution.
9 Select an appropriate method to solve a quadratic equation in one variable.
9.a 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.
9.b Solve quadratic equations by inspection (such as x2 = 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.
10 Select an appropriate method to solve a system of two linear equations in two variables.
10.a 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.
Expressions, equations, and inequalities can be used to analyze and make predictions, both within mathematics and as mathematics is applied in different contexts– in particular, contexts that arise in relation to linear, quadratic, and exponential situations.
11 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.
12 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.
13 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.
Functions shift the emphasis from a point- by-point relationship between two variables (input/output) to considering an entire set of ordered pairs (where each first element is paired with exactly one second element) as an entity with its own features and characteristics.
14 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.
16 Compare and contrast relations and functions represented by equations, graphs, or tables that show related values; determine whether a relation is a function. Explain that a function f is a special kind of relation defined by the equation y = f(x).
17.b Use function composition to combine different types of standard functions to write and evaluate functions.
Graphs can be used to obtain exact or approximate solutions of equations, inequalities, and systems of equations and inequalities – including systems of linear equations in two variables and systems of linear and quadratic equations (given or obtained by using technology).
18 Solve systems consisting of linear and/or quadratic equations in two variables graphically, using technology where appropriate.
20 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.
Functions can be described by using a variety of representations: mapping diagrams, function notation (e.g., f(x) = x2), recursive definitions, tables, and graphs.
21 Compare properties of two functions, each represented in a different way (algebraically, graphically, numerically in tables, or by verbal descriptions). Extend from linear to quadratic, exponential, absolute value, and general piecewise.
Functions that are members of the same family have distinguishing attributes (structure) common to all functions within that family.
23 Identify the effect on the graph of replacing f(x) by f(x) + k, k ⋅ f(x), f(k ⋅ x), 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 explain the effects on the graph, using technology as appropriate. Limit to linear, quadratic, exponential, absolute value, and linear piecewise functions.
25 Construct linear and exponential functions, including arithmetic and geometric sequences, given a graph, a description of a relationship, or two input-output pairs (include reading these from a table).
Functions can be represented graphically and key features of the graphs, including zeros, intercepts, and, when relevant, rate of change and maximum/minimum values, can be associated with and interpreted in terms of the equivalent symbolic representation.
28 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. Extend from relationships that can be represented by linear functions to quadratic, exponential, absolute value, and linear piecewise functions.
29 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. Limit to linear, quadratic, exponential, and absolute value functions.
Mathematical and statistical reasoning about data can be used to evaluate conclusions and assess risks.
32 Use mathematical and statistical reasoning with bivariate categorical data in order to draw conclusions and assess risk.
Making and defending informed, data- based decisions is a characteristic of a quantitatively literate person.
33 Design and carry out an investigation to determine whether there appears to be an association between two categorical variables, and write a persuasive argument based on the results of the investigation.
Focus 2: Visualizing and Summarizing Data
Data arise from a context and come in two types: quantitative (continuous or discrete) and categorical. Technology can be used to "clean" and organize data, including very large data sets, into a useful and manageable structure—a first step in any analysis of data.
34 Distinguish between quantitative and categorical data and between the techniques that may be used for analyzing data of these two types.
The association between two categorical variables is typically represented by using two-way tables and segmented bar graphs.
35 Analyze the possible association between two categorical variables.
35.a Summarize categorical data for two categories in two-way frequency tables and represent using segmented bar graphs.
35.b Interpret relative frequencies in the context of categorical data (including joint, marginal, and conditional relative frequencies).
35.c Identify possible associations and trends in categorical data.
Data analysis techniques can be used to develop models of contextual situations and to generate and evaluate possible solutions to real problems involving those contexts.
36 Generate a two-way categorical table in order to find and evaluate solutions to real-world problems.
36.a Aggregate data from several groups to find an overall association between two categorical variables.
36.b Recognize and explore situations where the association between two categorical variables is reversed when a third variable is considered (Simpson's Paradox).
Focus 3: Statistical Inference
Note: There are no Algebra I with Probability standards in Focus 3
Focus 4: Probability
Two events are independent if the occurrence of one event does not affect the probability of the other event. Determining whether two events are independent can be used for finding and understanding probabilities.
37 Describe events as subsets of a sample space (the set of outcomes) using characteristics (or categories) of the outcomes, or as unions, intersections, or complements of other events ("or," "and," "not").
Conditional probabilities – that is, those probabilities that are "conditioned" by some known information – can be computed from data organized in contingency tables. Conditions or assumptions may affect the computation of a probability.
39 Compute the conditional probability of event A given event B, using two-way tables or tree diagrams.