› algebra › discriminantFormula, Rules, Discriminant of Quadratic Qquation - Cuemath They can be found using the quadratic formula: x = \(\dfrac{-b \pm \sqrt{D}}{2 a}\). Though we cannot find the roots by just using the discriminant, we can determine the nature of the roots as follows. If Discriminant is Positive. If D > 0, the quadratic equation has two different real roots.