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X 2 +2x+y 2 =0 what is the center and radius of the circle?

User Ccallendar
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1 Answer

5 votes

Center = (-1,0) Radius= 1

when you complete the square your equation should look something like

(x²+2x+1) (y²+0) = 1.The 1 on the left side coming from (b/2)² which is (2/2)² which equals 1 and whatever you add to one side, you have to add to the other so when you add 0+1 you get the 1 on the right side. Then factor or use the (b/2) from earlier without the ² so you should get (x²+1) + (y²+0) = 1. Flip the sign so you have negative 1 and 0. For the radius, square the right side and of course,
√(1) is simply 1 so your radius is 1. A lot of 1's huh? lol at least it makes the operations nice and simple :)

User Yonatanmn
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