SOLVE EQUATIONS WITH ABSOLUTE VALUE. SOLVE INEQUALITIES WITH ABSOLUTE VALUE. Copyright © 2012...
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Transcript of SOLVE EQUATIONS WITH ABSOLUTE VALUE. SOLVE INEQUALITIES WITH ABSOLUTE VALUE. Copyright © 2012...
Solve equations with absolute value. Solve inequalities with absolute value.
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
3.5 Solving Equations and Inequalities with Absolute Value
Equations with Absolute Value
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
For a > 0 and an algebraic expression x:
| x | = a
is equivalent to
x = a or x = a.
Example
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
Solve: x 5.
Example
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
Solve: x 3 1 4.
More About Absolute Value Equations
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
When a = 0, | x | = a is equivalent to x = 0.
Note that for a < 0, | x | = a has no solution, because the absolute value of an expression is never negative.
The solution is the empty set, denoted .
Inequalities with Absolute Value
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
Inequalities sometimes contain absolute-value notation. The following properties are used to solve them.
For a > 0 and an algebraic expression x:
| x | < a is equivalent to a < x < a.
| x | > a is equivalent to x < a or x > a.
Similar statements hold for | x | a and | x | a.
Inequalities with Absolute Value
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
For example,
| x | < 3 is equivalent to 3 < x < 3
| y | ≥ 1 is equivalent to y ≤ 1 or y ≥ 1
| 2x + 3 | ≤ 4 is equivalent to 4 < 2x + 3 < 4
Example
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
Solve: Solve and graph the solution set:
3x 2 5.
Example
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
Solve: Solve and graph the solution set:
5 2x 1.
Absolute Value InequalitiesAbsolute Value Inequalities Absolute Value EquationsAbsolute Value Equations
Copyright © 2012 Pearson Education, Inc. Publishing as Addison Wesley
Practice