SOLUTION: i have to write the circle in standard form. then give the centeer and radius of the circle. x^2+y^2+8x-2y-8=0

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Question 69425: i have to write the circle in standard form. then give the centeer and radius of the circle. x^2+y^2+8x-2y-8=0
Found 2 solutions by Nate, funmath:
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 + 8x + y^2 - 2y = 8
(x + 4)^2 + (y - 1)^2 = 25
C(-4,1) with radius 5 units

Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
i have to write the circle in standard form. then give the centeer and radius of the circle.
The standard form of a circle is highlight%28%28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2%29, where (h,k) = center and r=radius.
x^2+y^2+8x-2y-8=0
Gather your x's and y's together and move the constant to the other side of the = sign.
x^2+8x+___+y^2-2y+___-8+8=0+8
Now complete the square, remember that whatever you do to one side of the equal sign you have to do to the other.
x^2+8x+____+y^2-2y+____=8
x^2+8x+(8/2)^2+y^2-2y+(-2/2)^2=8+(8/2)^2+(-2/2)^2
x^2+8x+(4)^2+y^2-2y+(-1)^2=8+(4)^2+(-1)^2
(x+4)^2+(y-1)^2=8+16+1
(x+4)^2+(y-1)^2=25
The center is: (h,k)=(-4,1)
The radius r=sqrt%2825%29=5
Happy Calculating!!!