Visualizing Absolute Values
Apart from polynomials there are different types of functions available in GeoGebra (e.g. trigonometric functions, absolute value function, exponential function). Functions are treated as objects and can be used in combination with geometric constructions.
Note: Some of the functions available can be selected from the menu next to the Input Bar. Please find a complete list of functions supported by GeoGebra in the GeoGebra Wiki.
Visualization of absolute values
Instructions
| 1. |  | Enter the absolute value function f(x) = abs(x). |
| 2. | | Enter the constant function g(x) = 3. |
| 3. |  | Intersect both functions. Hint: You need to intersect the functions twice in order to get both intersection points. |
| 4. |
| Enhance your construction using the Style Bar. Hint: You might want to close the Algebra View and show the names and values as labels of the objects. |
Try it yourself...
Back to school...
- Move the constant function g with the mouse or using the arrow keys. What is the relation between the y-coordinate and the x-coordinate of each intersection point?
- Move the absolute value function f up and down either using the mouse or the arrow keys. In which way does the function’s equation change?
- How could this construction be used in order to familiarize students with the concept of absolute value? Hint: The symmetry of the function graph indicates that there are usually two solutions for an absolute value problem.