Apr 5, 2016

#### Explanation:

D = d^2 = b^2 - 4ac (1)
$x = - \frac{b}{2 a} \pm \frac{d}{2 a}$ (2).

In this formula:
- Quantity $- \frac{b}{2 a}$ represents the x-coordinate of the axis of symmetry.
- Quantity $\pm \frac{d}{2 a}$ represents the distances from the axis of symmetry to the 2 x-intercepts.
$x = - \frac{b}{2 a} \pm \left(\frac{\sqrt{{b}^{2} - 4 a c}}{2 a}\right)$