Math Problem Statement

How to sketch absolute of y = f(x)

Solution

To sketch the graph of y=f(x)y = |f(x)|, follow these steps:

  1. Start by sketching y=f(x)y = f(x): Plot the original function as if the absolute value wasn’t present.

  2. Identify the negative portions of f(x)f(x): Locate where the graph of y=f(x)y = f(x) is below the x-axis (i.e., where f(x)<0f(x) < 0).

  3. Reflect the negative parts above the x-axis: For any xx where f(x)<0f(x) < 0, reflect the portion of the graph that is below the x-axis to make it positive. This means flipping it to the other side of the x-axis while maintaining its shape.

  4. Keep the positive parts unchanged: For the regions where f(x)0f(x) \geq 0, the graph remains as it is.

  5. Erase the parts below the x-axis: After reflecting, remove any parts of the graph that remain below the x-axis, since f(x)|f(x)| is always non-negative.

Example

If you have f(x)=x24f(x) = x^2 - 4, first sketch f(x)=x24f(x) = x^2 - 4, then reflect the part of the graph below the x-axis, and finally remove the portion that remains negative.


Do you want to go into more detail or ask any questions about these steps?

Here are 5 related questions to deepen understanding:

  1. What happens when the function f(x)f(x) is always positive?
  2. How does the graph of f(x)|f(x)| change if f(x)f(x) is a linear function?
  3. Can the graph of y=f(x)y = |f(x)| ever touch the x-axis?
  4. What are some common mistakes to avoid when sketching y=f(x)y = |f(x)|?
  5. How would the process differ for a piecewise function?

Tip: Always ensure the points where f(x)=0f(x) = 0 remain unchanged when sketching f(x)|f(x)|.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Absolute Value Functions
Graphing Functions
Reflection of Functions

Formulas

y = |f(x)|

Theorems

Properties of Absolute Value

Suitable Grade Level

Grades 9-11