SOLUTION: The equation {{{x^2 + y^2 - 2x + 8y + 8 = 0}}} is the equation of a circle. Complete the square to change this equation to standard form. Find the radius and the coordinates of the

Question 1033689: The equation is the equation of a circle. Complete the square to change this equation to standard form. Find the radius and the coordinates of the center of the circle.
Not sure what the first step would be to solve this problem. Any help would be great. Thank you :)
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
x^2 + y^2 - 2x + 8y + 8 = 0
----------------
Rearrange::
x^2 - 2x + y^2 + 8y = -8
------
Complete the square on the x-terms and on the y-terms ::
---------------------
x^2 - 2x +1 + y^2 + 8y + 16 = -8 + 1 + 16
-------------------------------------------
(x-1)^2 + (y+4)^2 = 9
---------
Center:: (1,-4)
radius:: sqrt(9) = 3
----------------------
Cheers,
Stan H.
--------------
RELATED QUESTIONS
The following equation is the general form of the circle 2x^2 - 5x + 2y^2 - 7y = 0.... (answered by Theo)

Complete the square and write the equation in standard form.Then give the center and... (answered by solver91311)

What is the equation in standard form for the circle:... (answered by Earlsdon)

Complete the square and write the equation in standard form. Then give the center and... (answered by orca)

Change the equation to standard form x^2+ y^2 - 2x + 14y + 1 =... (answered by Edwin McCravy)

Complete the square and write the equation of the circle in standard form. Then determine (answered by Cromlix)

C(7,4) is internally tangent to x^2+y^2+12x-8y+3=0. Find the equation of the... (answered by greenestamps)

Find the equation of all tangents to the circle x^2 + y^2 - 2x + 8y - 23 = 0 a) having... (answered by Alan3354)

Complete the square and write the equation of the circle into standard form.... (answered by Edwin McCravy)