System of linear equations

How to insert dynamic text

Dynamic text contains an element that refers to one of the objects used in the construction. Thus, the text adapts to changes of the object (e.g. new coordinates, area). Select the

Text tool and click in the

Graphics View. Click on Advanced and select tab

Objects. From the list of available objects, select the object which value should be displayed in the

Graphics View. Hint: You may also add static parts to your text. The dynamic part of your text will change, if the construction is modified.

Task

Create a dynamic figure that visualizes the solution of a system of linear equations. Note: Such a dynamic figure can also be used to visualize...

the solution of a system of functions.
an equation in one variable by entering each side of the equation as one of the two functions.

Explore the construction...

Instructions

1.		Enter the linear equation `line_1: y = m_1 x + b_1` into the Input Bar.
		Hint: The input `line_1` gives you line₁.
2.		GeoGebra will automatically create sliders for the variables m₁ and b₁when pressing Enter.
3.		Show the sliders in the Graphics View by clicking on the disabled Visibility buttons next to their entry in the Algebra View.
4.		Repeat steps 1 to 3 for the equation of `line_2: y = m_2 x + b_2`.
5.		Use the Style Bar to change the color of both lines and their sliders.

Try it yourself...

Instructions (continued)

6.		Use the Text tool and create a dynamic text by entering `Line 1:` in the appearing dialog and selecting line_1 from the list of objects on tab Objects of the Advanced section.
7.		Create a dynamic text with the static part `Line 2:` and select line_2 from the list of objects on tab Objects of the Advanced section.
8.		Use the Style Bar to match the color of the texts with their corresponding lines.
9.		Construct the intersection point A of both line₁ and line₂ by either using the Intersect tool, or by entering the command `Intersect(line_1, line_2)`into the Input Bar.
10.		Enter `xcoordinate = x(A)` into the Input Bar. Hint: x(A) gives you the x-coordinate of the intersection point A.
11.		Also, define `ycoordinate = y(A)`. Hint: y(A) gives you the y-coordinate of the intersection point A.
12.		Create a dynamic text with the static part `Solution: x =` and select xcoordinate from the list of objects on tab Objects.
13.		Create a dynamic text with the static part `y =` and select ycoordinate from the list of objects on tab Objects.
14.		Fix the texts so they can’t be moved accidentally by selecting the texts and opening the Style Bar.