Identify the radius and center.

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

Center:-1,-2

Radius: 2

Step-by-step 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