Absolute Value

Definition of Absolute Value

  • Absolute value of a number is its distance from zero on the number line. The absolute value of a number n is denoted by, |n|.
 

More about Absolute Value

  • Absolute value function is a piecewise function and is written as f (x) = |x|,

where f(x) ≥ 0 for all values of x.

This means that f (x) = - x for x < 0 or  x for x ≥ 0

  • Absolute Value Inequalities:
For all real numbers x and y, y > 0,
1. if |x | < y, then – y < x < y

2. if |x | > y, then x > y or x < - y

  • Absolute Value Equation: It is an equation of the form

|ax + b| = c.

                                           

Examples of Absolute Value

  • Absolute Value: The absolute value of – 5 is 5, because – 5 is 5 units away from zero on the number line.
The absolute value of 6 is 6, because 6 is 6 units away from zero on the number line.
  • Absolute Value Function: y = | x | + 3
  • Absolute Value Inequalities: | m | > 5
  • Absolute Value Equation: | x - 3| = 6
 

Solved Example on Absolute Value

Simplify the inequality |6 - x| - 3 > 2.

Choices:

A. x < -11 or x > - 1

B. x > 11 or x < 1

C. x < 11 or x > 1

D. None of these

Correct Answer: B

Solution:

Step 1: |6 - x| - 3 > 2 = |6 - x|> 5

Step 2: = - 5 > 6 - x > 5

Step 3: = - 5 - 6 > - x > 5 - 6

Step 4: = - 11 > - x > - 1

Step 5: = 11 < x < 1

Step 6: = x > 11 or x < 1

 

Related Terms for Absolute Value

  • Absolute Value Function
  • Piecewise Function
  • Absolute Value Equation
  • Absolute Value Inequality
  • Number Line
 

Additional Links for Absolute Value