SOLUTION: find the center and radius of y^2+x^2+9y-6x-10=0

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Question 175424: find the center and radius of y^2+x^2+9y-6x-10=0
Answer by Mathtut(3670) About Me  (Show Source):
You can put this solution on YOUR website!
y^2+x^2+9y-6x-10=0
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we need to complete the squares on the x and y terms
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x%5E2-6x%2B9%2By%5E2%2B9y%2B%2881%2F4%29-9-%2881%2F4%29-10=0adding and subtracting same terms to complete the square and to keep this an equivalent equation
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%28x-3%29%5E2%2B%28y%2B9%2F2%29%5E2=10%2B9%2B%2881%2F4%29completing square
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%28x-3%29%5E2%2B%28y%2B9%2F2%29%5E2=157%2F4combining terms on right
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radius is square root of the right side in this form.
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so the center is (3,-9/2) and the radius is sqrt%28157%2F4%29=6.26