Use the point tool to create a point A anywhere in the Graphics View with it.
Type x(A) in the Input line (bar), what happened in the Algebra View?
Type y(A) in the Input line (bar), what happened in the Algebra View?
Use the Move tool to grab point A and move it, what is happening in the Algebra View?
Now it is time to examine the inverse of point A. The inverse of A is a point that interchanges the x-coordinate and y-coordinate of a point. If point A (3,5), the inverse is point B (5,3).
Move point A to some point in Quadrant I, be sure that the value of the x-coordinate is different from the y-coordinate.
Use the Input bar to type.:
B = (y(A), x(A))
Observe the value of point B in the Algebra View.
Use the Move tool to move the point B. Describe what happens.
Now move point A, describe what happens.

This is a Java Applet created using GeoGebra from www.geogebra.org - it looks like you don't have Java installed, please go to www.java.com
This applet can be used by teachers in a demonstration mode in the classroom or teachers can have students load it on their own computers. A worksheet can be completed for a grade.