Learning Resources

Investigation 6: The Equation of a Circle

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In the diagram above the ^ symbol means to the power of. Thus x^2 means x².

Step 1: Write down the equation, the value of the radius and the radius squared.

Step 2: Drag point A to make the radius 1, 2, 3, 4, 5, 7, 9, 10 and 11. For each value write down the equation, the value of the radius and the radius
squared.

Question: Given an equation of a circle with centre at the origin, how do you determine the radius? What is the radius of x² + y² = 50?