Question

Find the center and radius for the circle by the equations: x2 + y2 + 5x - y + 2 = 0.

Answer 1

X2+5x+y2-y=-2
X2+2*5x2+(5/2)^2-(5/2)^2+y2-2*y/2+(1/2)^2-(1/2)^2=-2
(x+5/2)^2+(y-1/2)^2-13/2=-2
(x+5/2)^2+(y-1/2)^2=9/2
So centre =(-5/2,1/2)
Radius=(9/2)^(1/2)