# Create and Use a Dynagraph

Topic:
Algebra

## Create and Use a Dynagraph

To create a dynagraph, follow these instructions: 1. In a new browser window open geogebra.org and start graphing. 2. Select the Settings icon, show grid, and no grid to hide the grid. 3. Hide the y-axis by selecting Settings, Settings, y-Axis and uncheck the box Show y-Axis. 4. Select the point tool, and place a point on the x-axis. This should be point A. 5. Type in a function. You may start with f(x)=x^2. Later, we will hide this function. 6. We need a second line; so type y=2. 7. You want the output of the function, which is f(x) to show up on the line from step 6. To do this, create a point, B with x-coordinate as the function output, and y-coordinate as 2 (your line from step 6). So, you could type: B=(f(x(A)),2). 8. Create a vector to point from the input value, A to the output value, B by tyuping: vector(A,B) Now you can move point A and see how point B (the output of the function) responds. Try changing your function f(x)= to something different. Then explore what happens when you move A. For example: f(x)=x f(x)=x^2 f(x)=x^3 f(x)=|x| f(x)=floor(x) f(x)=ceiling(x) f(x)=round(x) f(x)=1/x f(x)=sin(x) f(x)=cos(x)