Determine the Center and radius of the circle and sketch the graph. x^2+y^2+6y=0

Question

i sort of have an idea of what its supposed to look like but im having trouble with this one.

Answer 1

Recall that (x-h)² + (y-k)² = r² is an equation of the circle with center (h,k) and radius r.  

 

x² + y² + 6y = 0

 

x² + y² + 6y + 9 = 9

 

(x-0)² + (y+3)² = 9

 

Center:  (0,-3)     Radius:  3