McGraw Hill Glencoe Algebra 2, 2012
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McGraw Hill Glencoe Algebra 2, 2012 View details
8. Graphing Linear and Absolute Value Inequalities
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Exercise 34 Page 120

Graph each case separately and then combine them. Begin by finding the boundary lines. Be careful about the domain of each case. When you test a point, choose the points from the corresponding domains.

Practice makes perfect

We have been given an inequality. g(x) > |x+1| if x≤ -4 - |x| if - 4 < x < 2 |x-4| if x ≥ 2 We will first graph each case of the inequality separately. Then we will combine them on the same coordinate plane. Let's start with the first case. We will begin by determining it boundary line. To do that we replace the inequality symbol with the equals sign. &Case I &&Boundary Line & g(x) > |x+1| && g(x) = |x+1|The graph of the boundary line is the graph of parent function f(x)=|x| translated 1 unit to the left. Since the inequality is strict, the boundary line will be dashed. Let's graph it!

For the first case, the domain is the x-values less than or equal to -4, so the boundary line will be bound by x=-4 on the right. We will indicate its right endpoint with a closed point because the inequality that represents the restriction is non-strict.

Now we will test a point to decide which region we should shade. Let's test the point (-5,5)!

g(x) > |x+1|
5 ? > | -5+1|
5 ? > |-4|
5> 4

The point satisfied the inequality, so we will shade the region that contains point.

Applying the same steps, other cases can be graphed.

Case Boundary Line Domain Transformation of f(x)=|x| Graph Testing a Point Inequality
g(x) > |x+1| g(x) = |x+1| x ≤ -4 Translation 1 unit to the left 5 ? > | -5+1| ⇓ 5> 4
g(x) > - |x| g(x) = - |x| -4 < x < 2 Reflection in the x-axis 2 ? > -| 0| ⇓ 2> 0
g(x) > |x-4| g(x) = |x-4| x ≥ 2 Translation 4 units to the right 4 ? > | 4-4| ⇓ 4> 0

Finally, we can combine the each case.