Question

Regina is trying to sketch a circle on graph paper with the equation x2+y2−2x+22y+1=0
. Calculate where she would need to graph the center and radius of the circle by completing the square.(1 point)

center= (1,−11)
, radius=11

center= (−1,11)
, radius=11

center= (−22,2)
, radius=41

center= (−2,22)
, radius=41

Answer 1

x^2+y^2−2x+22y+1=0
Rewrite and complete squares:
(x^2−2x+1) + (y^2+22y+121) +1−1−121 =0
=> (x−1)^2 + (y+11)^2 = 121

So center = (1, −11) and radius = 11.