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Absolute Value Function Transformations

Sep 3, 2025

Overview

This lecture explains how absolute value functions can be transformed through vertical and horizontal translations, and introduces related key terms.

Transforming Absolute Value Functions

  • Absolute value functions have the form f(x) = |x| and can be altered by translations, stretches, compressions, and reflections.
  • Transformations change the graph's position or shape on the coordinate plane.

Vertical Translation

  • Adding k to f(x) gives f(x) + k, shifting the graph up if k > 0 and down if k < 0.
  • Example: g(x) = |x| + 1 shifts the graph up by 1 unit; h(x) = |x| − 1 shifts the graph down by 1 unit.
  • The vertex moves from (0,0) to (0,k).

Horizontal Translation

  • Replacing x with (x − h) in f(x) gives f(x − h), shifting the graph right by h if h > 0 and left by h if h < 0.
  • Example: g(x) = |x + 1| shifts the graph left by 1 unit; h(x) = |x − 1| shifts the graph right by 1 unit.
  • The vertex moves from (0,0) to (h,0).

Combined Translation (Vertex Form)

  • The function g(x) = |x − h| + k shifts the graph h units horizontally and k units vertically.
  • The new vertex is at (h, k).

Key Terms & Definitions

  • Translation — Moving a graph up, down, left, or right without changing its shape.
  • Stretch — Making the graph narrower.
  • Compression — Making the graph wider.
  • Reflection — Flipping the graph over an axis.

Action Items / Next Steps

  • Practice identifying and graphing absolute value function translations.
  • Review definitions of translation, stretch, compression, and reflection.