Transformations of the Absolute Value Function

Algebra-1

1. Fundamental Concepts

  • Definition: The absolute value function, denoted as $$f(x) = |x|$$, represents the distance of a number from zero on the number line.
  • Transformations: Transformations of the absolute value function include shifts, stretches, and reflections which alter the graph's position and shape.
  • Shifts: Horizontal and vertical shifts are represented by adding or subtracting constants inside or outside the absolute value expression.

2. Key Concepts

Vertical Shift: $$f(x) = |x| + k$$

Adding \(k\) shifts the graph up by \(k\) units if \(k > 0\), and down by \(|k|\) units if \(k < 0\).

Horizontal Shift: $$f(x) = |x - h|$$

Subtracting \(h\) shifts the graph right by \(h\) units if \(h > 0\), and left by \(|h|\) units if \(h < 0\).

Reflection: $$f(x) = -|x|$$

Multiplying by \(-1\) reflects the graph over the x-axis.

3. Examples

Example 1 (Basic)

Problem: Graph the function $$f(x) = |x| + 3$$

Step-by-Step Solution:

  1. Start with the basic absolute value function $$y = |x|$$.
  2. Add 3 to every y-value, shifting the graph up by 3 units.
Validation: Check points such as (0, 3), (-1, 4), and (1, 4).

Example 2 (Intermediate)

Problem: Graph the function $$f(x) = |x - 2| - 1$$

Step-by-Step Solution:

  1. Start with the basic absolute value function $$y = |x|$$.
  2. Subtract 2 from every x-value, shifting the graph right by 2 units.
  3. Subtract 1 from every y-value, shifting the graph down by 1 unit.
Validation: Check points such as (2, -1), (1, 0), and (3, 0).

4. Problem-Solving Techniques

  • Graphical Analysis: Use a coordinate plane to visualize transformations step-by-step.
  • Point Substitution: Substitute specific values into the transformed function to find key points.
  • Pattern Recognition: Identify patterns in how transformations affect the graph’s shape and position.