Students will explore the equation of a circle in this applet. They will experiment with changing the values of the center point and the radius.

1. Make sure the “Task 2” box is unchecked.[br]2. Given the equation of a circle with the center at the origin, make a prediction about how the graph will be changed if r changes.[br]3. Move the slider r. How does the graph change when r is negative? How does it change when it is positive? Are there any two values for r in which the graph is the same?[br]4. Check the “Task 2” box. [br]5. Given the equation of a circle with center at (h,k), make a prediction about how the graph of the circle will change when h changes.[br]6. Move slider h. How does the graph change when h is larger? How does the graph change when h is smaller?[br]7. Next, make a prediction about how the graph of the circle will change when k changes.[br]8. Move slider k. How does the graph change when k is larger? How does the graph change when k is smaller?