In Exercises 77–92, use the graph to determine a. the function's domain; b. the function's range; c. the x-intercepts, if any; d. the y-intercept, if any; and e. the missing function values, indicated by question marks, below each graph.
Ch. 2 - Functions and Graphs

Chapter 3, Problem 91
Use the graphs of f and g to evaluate each composite function.

(fog) (-1)
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Step 1: Understand the composite function (fog)(-1). This means we first evaluate g(-1) and then use that result as the input for f(x).
Step 2: Locate the value of g(-1) on the graph of g(x) (blue curve). Find the x-coordinate of -1 and determine the corresponding y-value.
Step 3: Use the y-value obtained from g(-1) as the input for f(x). Locate this value on the graph of f(x) (red curve) and determine the corresponding y-value.
Step 4: The final y-value obtained from f(g(-1)) is the result of the composite function (fog)(-1).
Step 5: Ensure all values are correctly read from the graph and verify the steps to avoid errors in interpretation.

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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Composite Functions
A composite function is formed when one function is applied to the result of another function. It is denoted as (f ∘ g)(x), meaning f(g(x)). To evaluate a composite function, you first find the output of g for a given input, and then use that output as the input for f.
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Function Composition
Function Evaluation
Function evaluation involves substituting a specific value into a function to determine its output. For example, if f(x) = 2x + 3, evaluating f(-1) means substituting -1 for x, resulting in f(-1) = 2(-1) + 3 = 1. This process is crucial for finding values in composite functions.
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Evaluating Composed Functions
Graph Interpretation
Interpreting graphs of functions involves understanding how the visual representation relates to the function's behavior. For the functions f and g shown in the graph, one must identify the values of f and g at specific points, which aids in evaluating composite functions by tracing the outputs visually.
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Guided course
Graphs and Coordinates - Example
Related Practice
Textbook Question
Textbook Question
Use the graphs of f and g to solve Exercises 83–90.
Graph f-g.
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Textbook Question
In Exercises 77–92, use the graph to determine a. the function's domain; b. the function's range; c. the x-intercepts, if any; d. the y-intercept, if any; and e. the missing function values, indicated by question marks, below each graph.
Textbook Question
In Exercises 77–92, use the graph to determine a. the function's domain; b. the function's range; c. the x-intercepts, if any; d. the y-intercept, if any; and e. the missing function values, indicated by question marks, below each graph.
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Textbook Question
Let f(x) = x² − x + 4 and g(x) = 3x – 5. Find g (1) and f(g(1)).
Textbook Question
Begin by graphing the absolute value function, f(x) = |x|. Then use transformations of this graph to graph the given function. h(x) = 2|x+3|
