Given the equation of a circle: (x-3)^2+(y+2)^2=25(x−3)2+(y+2)2=25, how do you find the center and the radius?

1 Answer
Alan P.
Dec 9, 2015

center: (3,-2)(3,−2)
radius: 55

Explanation:

The general form for the equation of a circle with center (color(red)(a),color(blue)(b))(a,b) and radius color(green)(r)r is
color(white)("XXX")(x-color(red)(a))^2+(y-color(blue)(b))^2=color(green)(r)^2XXX(x−a)2+(y−b)2=r2

(x-3)^2+(y+2)^2=25(x−3)2+(y+2)2=25
can be easily transformed into the general form as:
color(white)("XXX")(x-color(red)(3))^2+(y-color(blue)((-2)))^2=color(green)(5)^2XXX(x−3)2+(y−(−2))2=52

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