Table of contents
- 0. Review of Algebra4h 16m
- 1. Equations & Inequalities3h 18m
- 2. Graphs of Equations43m
- 3. Functions2h 17m
- 4. Polynomial Functions1h 44m
- 5. Rational Functions1h 23m
- 6. Exponential & Logarithmic Functions2h 28m
- 7. Systems of Equations & Matrices4h 6m
- 8. Conic Sections2h 23m
- 9. Sequences, Series, & Induction1h 19m
- 10. Combinatorics & Probability1h 45m
3. Functions
Intro to Functions & Their Graphs
Problem 19c
Textbook Question
Determine whether each relation defines a function, and give the domain and range. See Examples 1–4. {(1,1),(1,-1),(0,0),(2,4),(2,-4)}
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<Step 1: Understand the definition of a function. A relation is a function if each input (or x-value) is associated with exactly one output (or y-value).>
<Step 2: Examine the given set of ordered pairs: \{(1,1), (1,-1), (0,0), (2,4), (2,-4)\}.>
<Step 3: Check for repeated x-values with different y-values. Notice that the x-value 1 is paired with both 1 and -1, and the x-value 2 is paired with both 4 and -4.>
<Step 4: Conclude that the relation does not define a function because there are x-values with more than one corresponding y-value.>
<Step 5: Identify the domain and range. The domain is the set of all x-values: \{1, 0, 2\}. The range is the set of all y-values: \{1, -1, 0, 4, -4\}.>
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Definition of a Function
A function is a specific type of relation where each input (or domain element) is associated with exactly one output (or range element). This means that for any given x-value, there cannot be multiple corresponding y-values. Understanding this definition is crucial for determining whether a relation qualifies as a function.
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Domain and Range
The domain of a relation is the set of all possible input values (x-values), while the range is the set of all possible output values (y-values). Identifying the domain and range helps in understanding the behavior of the function and its limitations. For the given relation, one must extract these sets from the ordered pairs.
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Ordered Pairs
Ordered pairs are pairs of numbers written in the form (x, y), where x is the first element and y is the second. In the context of relations, each ordered pair represents a connection between an input and an output. Analyzing these pairs is essential for determining if a relation is a function and for identifying the domain and range.
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