
Philip P. answered 05/12/14
Tutor
5.0
(478)
Effective and Patient Math Tutor
y2+8y+41=0
y2 + 8y = -41
To complete the square, take 1/2 of the coefficient of the y term (8y) and square it = (8/2)2. You need to add it to both sides of the equation to keep things equal.
y2 + 8y + (8/2)2 = -41 + (8/2)2
y2 + 8x + 16 = -41 + 16
(y+4)2 = -25
y+4 = ±5i [Took the square root of both sides]
y = -4+5i, -4-5i