# How do you find the x intercepts for f(x) = -x^2 + 6x + 8?

$D = {d}^{2} = 36 + 32 = 68 = 4 \left(17\right) \to d = \pm 2 \sqrt{17.}$
$x = - \frac{b}{2 a} \pm \frac{d}{2 a} = 2 \pm \sqrt{17}$