1. The formula used to calculate the roots of a quadratic equation $ax^2 + bx + c = 0$ is called the Quadratic Formula. 2. The formula is: $$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ 3. Here, $a$, $b$, and $c$ are coefficients from the quadratic equation. 4. The symbol $\pm$ means there are generally two solutions: one with a plus and one with a minus. 5. The term under the square root, $b^2 - 4ac$, is called the discriminant, which determines the nature of the roots. 6. If the discriminant is positive, there are two distinct real roots. 7. If it is zero, there is exactly one real root (a repeated root). 8. If it is negative, the roots are complex conjugates.