The Equation of a Circle
Form of the equation
(x - h)2 + (y - k)2 = R2
where the center is at (h, k) and the radius is R.
Remember - the signs of the center are switched !
Try it! Drag the sliders to change the center and radius of the circle. use the + and - tools to zoom in and out.
Answer these !
1. What is the radius if the circle whose equation is (x - 1)2 + (y - 4)2 = 25
What is the center of the circle whose equation is (x + 3)2 + (y - 5)2 = 36