The roots of polynomial $ p(x) $ are:
$$ \begin{aligned}x_1 &= 5.4142\\[1 em]x_2 &= 2.5858 \end{aligned} $$The solutions of $ x^2-8x+14 = 0 $ are: $ x = 4-\sqrt{ 2 } ~ \text{and} ~ x = 4+\sqrt{ 2 }$.
You can use step-by-step quadratic equation solver to see a detailed explanation on how to solve this quadratic equation.