Chapter 8 - Section 8.2 - The Quadratic Formula - Exercise Set - Page 607: 13

{$2 - 2i,2 + 2i$} or, {$2(1-i),2(1+i)$}

Quadratic formula suggests that $x=\dfrac{-b \pm \sqrt{b^2-4ac}}{2a}$ Since, $x^2-4x+8=0$ Thus, $x=\dfrac{-(-4) \pm \sqrt{(-4)^2-4(1)(8)}}{2(1)}$ or, $x=\dfrac{4 \pm \sqrt{-16}}{2}$ or, $x=2 \pm 2i$ or, $x=2 - 2i,2 + 2i$ Our solution set is: {$2 - 2i,2 + 2i$} or, {$2(1-i),2(1+i)$}