Equation & Graph of a Circle

The following applet was designed to help you see the relationship between the equation of a circle and its graph. Adjust the sliders "h", "k", and "r" (one at at time), and observe what happens to the graph and equation after altering each one. Answer the questions below.

Questions: 1) What does the parameter "h" in the equation of a circle tell you about the graph of the circle itself? 2) What does the parameter "k" in the equation of a circle tell you about the graph of the circle itself? 3) What does the parameter "r" in the equation of a circle tell you about the graph of the circle itself? 4) How is the value of "r" made evident in the equation?


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