SOLUTION: Identify the conic section. If it is a parabola, give the vertex. If it is a circle, give the center and radius. If it is an ellipse or a hyperbola, give the center and foci.

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Identify the conic section. If it is a parabola, give the vertex. If it is a circle, give the center and radius. If it is an ellipse or a hyperbola, give the center and foci.       Log On


   

Question 555079: Identify the conic section. If it is a parabola, give the vertex. If it is a circle, give the center and radius. If it is an ellipse or a hyperbola, give the center and foci.

x^2+y^2+8x-4y=-11


a)circle; center (–4, 2); radius = 9
b)circle; center (4, –2); radius = 9
c) circle; center (–4, 2); radius = 3
d) circle; center (4, –2); radius = 3
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!

Identify the conic section. If it is a parabola, give the vertex. If it is a circle, give the center and radius. If it is an ellipse or a hyperbola, give the center and foci.
x^2+y^2+8x-4y=-11
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Complete the square.
x%5E2%2By%5E2%2B8x-4y=-11+
x%5E2%2B8x%2B16+%2B+y%5E2-4y%2B4+=+9
%28x%2B4%29%5E2+%2B+%28y-2%29%5E2+=+3%5E2
It's c.