Skip to main content
Ch. 2 - Functions and Graphs
Blitzer - College Algebra 8th Edition
Blitzer8th EditionCollege AlgebraISBN: 9780136970514Not the one you use?Change textbook
Chapter 3, Problem 92

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|

Verified step by step guidance
1
Start by graphing the parent function f(x) = |x|. This is a V-shaped graph with its vertex at the origin (0, 0). The graph opens upwards, with a slope of 1 for x > 0 and a slope of -1 for x < 0.
Next, analyze the transformation inside the absolute value function. The term (x + 3) indicates a horizontal shift. Specifically, the graph of f(x) = |x| is shifted 3 units to the left. This means the vertex of the graph moves from (0, 0) to (-3, 0).
Now, consider the coefficient 2 outside the absolute value function. This represents a vertical stretch. The graph of f(x) = |x| is stretched by a factor of 2, meaning the slopes of the lines become steeper: 2 for x > -3 and -2 for x < -3.
Combine the transformations: Start with the vertex at (-3, 0), apply the vertical stretch, and ensure the slopes of the graph are adjusted accordingly. The left side of the graph will have a slope of -2, and the right side will have a slope of 2.
Finally, sketch the transformed graph h(x) = 2|x + 3| by applying the horizontal shift and vertical stretch to the parent function. Verify that the vertex is at (-3, 0) and the slopes are consistent with the transformations.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
6m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Absolute Value Function

The absolute value function, denoted as f(x) = |x|, outputs the non-negative value of x. This function has a V-shaped graph that intersects the origin (0,0) and is symmetric about the y-axis. Understanding this function is crucial as it serves as the foundation for graphing transformations.
Recommended video:
4:56
Function Composition

Transformations of Functions

Transformations involve shifting, stretching, or reflecting the graph of a function. For the function h(x) = 2|x+3|, the graph of f(x) = |x| is first shifted left by 3 units and then vertically stretched by a factor of 2. Recognizing these transformations allows for accurate graphing of modified functions.
Recommended video:
4:22
Domain & Range of Transformed Functions

Graphing Techniques

Graphing techniques include plotting key points, identifying transformations, and understanding the behavior of functions. For h(x) = 2|x+3|, one must first graph the base function and then apply the transformations systematically. Mastery of these techniques is essential for visualizing and interpreting the behavior of complex functions.
Recommended video:
Guided course
02:16
Graphs and Coordinates - Example