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Mathematics LibreTexts

2.2: Domain and Range

  • Page ID
    203383
    • Roy Simpson, Cosumnes River College
    • OpenStax

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    Prerequisite Skills
    • Sets and Numbers
      • Inequalities and Inequality Notation
      • Intervals and Interval Notation
    • Factoring Techniques
      • Factoring Difference of Squares
    • Solving Inequalities
      • Solving Linear Inequalities
      • Solving Compound Inequalities
      • Solving Quadratic Inequalities (sign chart method)
    • Graphs
      • Closed- and Open-Circle Notations

    Finding the Domain of a Function Defined by an Equation

    MyOpenMath \( \PageIndex{ 3 } \): Finding the domain and range of a relation given as a set of ordered pairs

    MyOpenMath \( \PageIndex{ 9 } \): Finding the domain of a quadratic function

    MyOpenMath \( \PageIndex{ 11 } \): Finding the domain of a rational function

    MyOpenMath \( \PageIndex{ 15 } \): Finding the domain of a function with an even root

    Using Notations to Specify Domain and Range

    Definition: Set-Builder Notation

    Set-builder notation is a notation for specifying a set by a property that characterizes its members.

    Example: Using different notations

    State the solution to the last example using interval, inequality, and set-builder notations.

    Finding Domain and Range from Graphs

    MyOpenMath \( \PageIndex{ 6 } \): Finding domain and range from a graph

    Finding Domains and Ranges of the Toolkit Functions

    Let's state the domains and ranges of the Toolkit functions.

    Graphing Piecewise-Defined Functions

    Definition: Piecewise Function

    A piecewise function (also called a piecewise-defined function) is a function whose domain is partitioned into several intervals ("subdomains") on which the function may be defined differently.

    MyOpenMath \(\PageIndex{16}\): Evaluating piecewise functions

    Example: Writing a piecewise function

    A museum charges $5 per person for a guided tour with a group of 1 to 9 people or a fixed $50 fee for a group of 10 or more people. Write a function relating the number of people, \( n \), to the cost, \( C \).

    MyOpenMath \( \PageIndex{ 18 } \): Graphing a piecewise function

    Definition: Absolute Value Function

    The absolute value function is defined to be \( f(x) = |x| \), where\[ |\blacksquare| = \begin{cases}
    \blacksquare, & \text{ if } \blacksquare \geq 0 \\[6pt]
    -\blacksquare, & \text{ if } \blacksquare < 0 \\[6pt]
    \end{cases} \nonumber \]


    This page titled 2.2: Domain and Range is shared under a CC BY-SA 4.0 license and was authored, remixed, and/or curated by Roy Simpson, Cosumnes River College (OpenStax) via source content that was edited to the style and standards of the LibreTexts platform.