SOLUTION: Please help me with this problem: Determine whether the equation x^2+y^2-4x+2y=9 represents a circle, a point, or no graph. I know that if there's a graph it should represent a

Algebra ->  Circles -> SOLUTION: Please help me with this problem: Determine whether the equation x^2+y^2-4x+2y=9 represents a circle, a point, or no graph. I know that if there's a graph it should represent a       Log On


   

Question 992559: Please help me with this problem: Determine whether the equation x^2+y^2-4x+2y=9 represents a circle, a point, or no graph.
I know that if there's a graph it should represent a circle, but i'm having trouble factoring properly.
Thanks!
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Determine whether the equation x^2+y^2-4x+2y=9 represents a circle, a point, or no graph.
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Complete the square on the x and on the y terms::
x^2-4x+4 + y^2+2y+1) = 9+4+1
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(x-2)^2 + (y+1)^2 = 14
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Circle with center at (2,-1) and radius = sqrt(14)
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Cheers,
Stan H.
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