Working with Geogebra Introduction

Welcome all of you 😊

With this introduction you’ll get basic informations about the use and the possibles of GeoGebra.

We work with Geogebra classic 5. The language will be set into English.

You can watch the file Geog_SetLanguage.mp4 to learn how to change the language.

#1      Set the language to English.

Now you’re ready to start with Geogebra. You’ll begin easy with some basics.

Basics for functions

You can make all these tasks if you  already now how to work with Geogebra, make sure you’re partner also understands! So the most important goal here is to get on the same level. If you both don’t know how to fulfil the tasks you can watch the video. You still don’t know? Ask a teacher. Have fun.

#2 Make a graph of f(x)= x² -3x+2. Save the file as task2.ggb

This was a rather simple function and you wouldn’t need Geogebra to plot it. And you could have guessed it would become more interesting if we introduce a parameter p in the function.

We will discover the function: f_p(x)= x² + p x +2 

#3 Make a graph of  f_p(x)= x² + p x +2. Create a slidebar for -5≤p≤5. Save the file as task3.ggb

(If you don’t succeed you can watch Geog_ParameterFunction.mp4)

If you change the parameter you’ll discover the top will move. The top seems to be located like: Y_top= - x² +2

#4 Plot Y_top= - x² +2 in the previous file. Slide the bar and agree that

      Y_top= - x² +2. could be right. Save the file as task4.ggb

(If you don’t succeed you can watch Geog_YtopParameter.mp4)

Of course we want to be sure that our discovery is correct. So….what do we know about tops? The derived function f'(x) should be 0. If you solve that equation you can conclude that p=-2x. Substitute p=-2x in f_p(x)= x² + p x +2 and you proved your discovery.

#5 Write down the prove that Y_top= - x² +2. You can write on paper.

Basics for geometry

So in this paragraph you’re going to create some nice figures. Lines, rectangles, triangles, parallel lines, angle-bisectors and many more.

We don’t need the algebra-window and we don’t need the fancy lined background and axes for geometry.

Watch the video Geog_GeometrySheet.mp4

 #6 Create a geometry-sheet without axes and lined background.

#7 Draw a circle. Create a triangle on the circle. Save the file as task7.ggb

(If you don’t succeed you can watch Geog_TriangleOnCircle.mp4)

#8 Draw the three angle bisectors in the triangle. If you change the triangle you can see that the angle bisectors still intersect in one point. You can animate the triangle so it moves automatically. Save the file as task8.ggb

(If you don’t succeed you can watch Geog_TriangleAnimation.mp4)

Geogebra has also a nice option to create regular polygons without a lot of work.

 #9 Create a triangle with an angel of 90°.  Create an regular hexagon on each side of the triangle. Save the file as task9.ggb

(If you don’t succeed you can watch Geog_HexagonOnTriangle.mp4)

Yellow and blue makes green, doesn’t it?

 #10  Measure the area of the three hexagons. What did you discover? Save the file as task10.ggb

(If you don’t succeed you can watch Geog_HexagonOnTriangleArea.mp4)

The Dutch team wishes you a lot of fun practicing GeoGebra.