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Ch. 2 - Graphs and Functions
Lial - College Algebra 13th Edition
Lial13th EditionCollege AlgebraISBN: 9780136881063Not the one you use?Change textbook
Chapter 3, Problem 17

Graph each function. See Examples 1 and 2. ƒ(x)=3|x|

Verified step by step guidance
1
Understand the function given: \(f(x) = 3|x|\). This means the output is three times the absolute value of \(x\).
Recall the shape of the basic absolute value function \(|x|\), which forms a 'V' shape with its vertex at the origin (0,0).
To graph \(f(x) = 3|x|\), multiply the output of \(|x|\) by 3, which vertically stretches the graph by a factor of 3. This makes the 'V' shape steeper.
Plot key points to guide your graph: for example, when \(x=0\), \(f(0) = 3|0| = 0\); when \(x=1\), \(f(1) = 3|1| = 3\); and when \(x=-1\), \(f(-1) = 3| -1| = 3\).
Draw the graph by connecting these points with straight lines forming a 'V' shape, ensuring the vertex is at the origin and the arms rise steeply due to the factor of 3.

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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 |x|, outputs the non-negative value of x regardless of its sign. It creates a V-shaped graph symmetric about the y-axis, reflecting all negative inputs as positive outputs.
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Function Composition

Vertical Stretching of Functions

Multiplying a function by a constant greater than 1, like 3 in 3|x|, stretches the graph vertically. This means all output values are scaled by that factor, making the graph steeper compared to the parent function.
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Stretches & Shrinks of Functions

Graphing Piecewise Functions

Absolute value functions can be viewed as piecewise functions with different expressions for x ≥ 0 and x < 0. Understanding this helps in plotting points accurately and visualizing the graph's shape.
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Graphs of Logarithmic Functions