Question

Solve for x in the equation x squared minus 8 x + 41 = 0.
x = negative 4 plus-or-minus StartRoot 37 EndRoot i
x = –4 ± 5i
x = 4 plus-or-minus StartRoot 37 EndRoot i
x = 4 ± 5i

Answer 1

Solve by completing the square:
x^2 − 8x + 41 = 0
(x − 4)^2 − 16 + 41 = 0 → (x − 4)^2 + 25 = 0
(x − 4)^2 = −25 → x − 4 = ±5i → x = 4 ± 5i.

So the correct choice is: x = 4 ± 5i.