Core Connections Algebra 1, 2013
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Core Connections Algebra 1, 2013 View details
3. Section 11.3
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Exercise 117 Page 563

Start with determining the boundary line. Then test a point to decide which side of the boundary line should be shaded.

Practice makes perfect

Graphing an absolute value inequality involves two main steps.

  1. Draw the boundary line.
  2. Determine which portion of the plane we should shade to show the solution set.

Boundary Line

The boundary line of an inequality can be determined by replacing the inequality symbol with an equals sign. cc Inequality & Boundary Line [0.5em] y > |x-2|+1 & y = |x-2|+1

To graph the given absolute value function, let's make a table of values first!

x |x-2|+1 Simplify y=|x-2|+1
0 | 0-2|+1 2+1 3
1 | 1-2|+1 1+1 2
2 | 2-2|+1 0+1 1
3 | 3-2|+1 1+1 2
4 | 4-2|+1 2+1 3

We will plot these ordered pairs on a coordinate plane and connect them to get the graph of the given function. Notice that the function is a transformation of the parent function f(x)=|x|, which is V-shaped. Thus, the given function will also be a V-shaped graph.

Shading the Solution Set

In order to decide which part of the plane to shade, we can test a point which is not on the boundary line. Let's test the point ( 0, 0).

If the point satisfies the inequality, we shade the region that contains the point. Otherwise, we shade the region that does not contain the point.
y > |x-2|+1
0 ? > | 0-2|+1
â–Ľ
Simplify
0 ? > |- 2|+1
0 ? > 2+1
0 ≯ 3
Since the point does not satisfy the inequality, we will shade the region that does not contain the point.