## GeoGebra 4.2 Tutorials, Now Available

It’s almost a month now since the release f GeoGebra 4.2 and since then I have updated tutorials to the said version. The update to version 4.2 of the GeoGebra Essentials Series and the GeoGebra Basic Geometric Construction Series are now complete.

I will be updating the GeoGebra Intermediate Tutorial Series and the GeoGebra Advanced Series after Christmas. Hopefully, I will be able to finish them before new year.

For now, let’s enjoy the holidays with our families.  Have a blessed Christmas and a prosperous New Year to all.

## GeoGebra 4.2 Sneak Peek 5: Ten New Improvements

This is the fifth and final  part of the GeoGebra 4.2 Sneak Peek Series.  In this post, I am going to list miscellany of significant improvements in GeoGebra 4.2.

1. The Delete tool can now be used like an electronic whiteboard eraser tool. To delete objects, just click the Delete tool and drag across the objects you want to delete.
2. It is now possible to translate an object by dragging using the Translate by Vector tool. No need to construct the Vector tool!
3. The objects in the Algebra view can now be sorted based on Construction Order and Layer. This arrangement is in addition to the previous sort categories which are by Dependency and Object Type.
4. The new Freehand tool allows drawing and converts it to an exact shape. For example, you can sketch a circle, and after than, GeoGebra will automatically draw  a circle based on your sketch.
5. Integration of colored commands in Latex. It is now possible to use colors in Latex commands such \green.
6. Ninety three new commands mostly on Statistics.
7. A share button in the Manage Tools  menu. This will enable users to share created customized buttons.
8. Letters without spaces now works. Before, to multiply a and b, we have to type * in between. Now, we can just type ab.
9. More supported languages.. For my Filipino readers, yes Filipino will be included and I am one of the translators.
10. Countif command. Well, this is a personal choice. I’ve been waiting for this command since the integration of spreadsheet.

This concludes the GeoGebra 4.2 Sneak Peek Series. If you want to read the details about the new version, you can read the GeoGebra 4.2 Release notes.

## GeoGebra Tutorial 4 – Graphs and Sliders

This is the fourth tutorial in the GeoGebra Intermediate Tutorial Series. If this is your first time to use GeoGebra, please read the GeoGebra Essentials Series first.

In this tutorial, we  use GeoGebra to investigate the effects of parameters of the equations of functions to the appearance of their graphs.  First, we type equations $y = mx$ and then use a slider investigate the effects of $m$.

Graphing Functions

1. Open GeoGebra and be sure the the Algebra and Graphics view is selected for the Perspective menu.
2. To graph $y = 2x$, type y = 2x in the input field. (The input field is the text box with the label Input located at the bottom of your GeoGebra window.) Press the ENTER key on your keyboard.
3. Type the following equations: y = 3x, y = 4x , y = -8x, and press the ENTER key after each equation.
4. Type more equations of the form $y = mx$ where $m$ is any real number.
5. How does the value of $m$affect the appearance of the graph of the function $y = mx$?

Using Sliders

To avoid typing over and over again for varying values $m$, we use the slider tool.  A slider is a visual representation of a number. This time, we add the parameter b. This means that we will explore the graph of the function of $y = mx + b$, where $m$ and $b$ are real numbers.

Instructions

 1.) Open the GeoGebra and be sure that Algebra View is selected from the Perspective menu. You can also do this by selecting Algebra from the view menu. 2.) Select the Slider tool and click on the Graphics view to display the Slider dialog box. 3.) In the Slider dialog box, change the slider’s name to m, change the interval to $-10$ to $10$ as shown below. Leave the other values as is and click the Apply button to finish. 4.) Adjust the position of your slider if necessary. Move the small black circle on your slider. What do you observe? 5.) To graph the function $y = mx$,  type y = mx in the Input box located at the bottom of the window. If the Input bar is not displayed, you can display it using the View menu. 6.) Now, Move the small circle on your slider. What do you observe? 7.) Now, create a new Slider and name it $b$. Set the interval to $-10$ and $10$ and leave the other values as they are. 8.) To change the function to $y = mx + b$, double click the graph to display the Redefine window, and then type y = mx + b. 9.) Now, move your $b$ slider. What do you observe? 10. ) How does the value of $b$ affect the appearance of the graph of the function $y = mx + b$? 11.)  As an exercise, graph the function $y = ax^2 + b$. Explain the effects of the parameters $a$ and $b$ to the graph of the function.

Notes:

1. The ^ symbol is used for exponentiation. Hence, we write $ax^2 + c$ as a*x^2 + c.
2. Instead of using $y$ in writing equations of functions, you can also use $f(x)$ for the function $f$.

Last Update: November 12, 2014 for GeoGebra 5.0.