Question

Identify the radius and center.


x^2 + y^2 + 2x + 4y + 1 = 0

Answer 1

Center:-1,-2

Radius: 2

Explanation:

Ok, get the form of a circle from this equation-

(x+2)^2+(y+2)^2=4

Since this is the form of a circle, I can figure out the center and the radius from here,

r=2

h=-1

k=-2

Center:-1,-2

Radius: 2