- Graph the boundary .
- The vertex is , and the two arms have slopes and .
- Use a solid V because includes equality.
Graphing Absolute-Value Inequalities
Graph the transformed V-shaped boundary, decide whether it is solid or dashed, test one ordered pair, and shade the complete two-variable solution region.
01 · Watch
Lesson video
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02 · Understand
Learning targets
- Rewrite an absolute-value inequality as its boundary equation.
- Use vertex form and slopes to graph the V-shaped boundary.
- Choose a solid or dashed boundary from the inequality symbol.
- Test an ordered pair and shade the complete solution region.
03 · Vocabulary
Key definitions
Connect the inequality to its boundary and shaded region.
- 01Boundary equation
- Replace the inequality symbol with to graph the curve that separates the plane.
- 02Solid boundary
- Use a solid curve for or because equality includes boundary points.
- 03Dashed boundary
- Use a dashed curve for or because boundary points are not solutions.
- 04Test point
- An ordered pair not on the boundary that determines which side makes the inequality true.
- 05Solution region
- Every shaded ordered pair that makes the original inequality true.
04 · Apply
Worked examples
These are the two examples developed in the lesson.
The statement is true, so shade the side of the solid V containing the origin.
- Graph the boundary .
- The vertex is . The negative coefficient reflects the V, and the arm slopes have magnitude .
- Use a dashed V because is strict.
The statement is false, so shade the region on the opposite side of the dashed V.
05 · Avoid
Common mistakes
Replace the symbol with equality first.
Equality means solid; a strict inequality means dashed.
In , the horizontal coordinate is .
Pick any ordered pair that is clearly off the V.
Substitute into the original inequality, not the equation.
Use a test point; transformations can move or reflect the V.
06 · Check yourself
Quick check
Predict the boundary before opening each answer.
1For , identify the vertex and line style.
Vertex ; solid V. The symbol includes equality.
2For , identify the vertex, orientation, and line style.
Vertex ; upside-down dashed V.
3Does satisfy ?
Yes. is true, so shade the side containing the origin.
4Why is one test point enough?
The continuous boundary separates the plane into regions. Every point in one region gives the same true-or-false result until the boundary is crossed.
07 · Revisit
Transcript and assigned practice
Search the corrected transcript for either example, then complete the eKadence worksheet Absolutevaluefunctioninequalities.pdf.
Download corrected transcript