SOLUTION: x^2 + y^2 -2x +2y -18 = 0 I need to find the center and radius of the circle

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Question 1028352: x^2 + y^2 -2x +2y -18 = 0
I need to find the center and radius of the circle
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Complete the Squares and put into standard form; and read the center (h,k) and radius r directly from the equation.

x%5E2-2x%2By%5E2%2B2y=18
x%5E2-2x%2B1%2By%5E2%2B2y%2B1=18%2B1%2B1-----*
%28x-1%29%5E2%2B%28y%2B1%29%5E2=20

Radius size is 2%2Asqrt%285%29 and center of the circle is (1,-1).



* Why this step was done is shown here: A lesson which includes how to Complete The Square