rearrange things a bit to get
x^2+8x + y^2+2y = -8
Now complete the squares:
x^2+8x+16 + y^2+2y+1 = -8 + 16 + 1
(x+4)^2 + (y+1)^2 = 9
center at (-4,-1)
when y=0,
(x+4)^2 + 1 = 9
(x+4) = ±√8
x = -4 ± √8
similarly for y when x=0
write the equation of the circle in standard form find the center radius, intercept and graph circle
x^2 +y^2+8x+2y+8=0
1 answer