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LB The Circle Centre (h,k) Radius r

Author:Louise Boyle

Topic:Coordinates

Move the centre of the circle to (1,1) and make the radius 4. What do you notice about the equation of that circle?

Play around with the applet by changing the centre and radius while paying particular attention to the equation of the corresponding equation of the circle. What do you notice?

General equation of a circle

What is the general equation of a circle has centre (h,k) and radius r?

Select all that apply

A
x²+ y²= r²
B
(x-h)²+( y-k)²= r²
C
(x+h)²+( y+k)²= r²
D
x-h²+y-k²= r²

Check my answer (3)

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