Solving quadratic equations


Home | History of quadratic equation | Vieta theorem |

Quadratic equation is an equation of the form ax2 + bx + c = 0, where a is not equal to 0.

You can use the following formulas for solving quadratic equations:

x1 and x2
where D = b2 - 4ac — is a discriminant of a polynomial ax2 + bx + c.
If D > 0, then an equation has two different real roots.
If D = 0, then both roots are real and equal.
If D < 0, then both roots are complex numbers.

In order not to make calculations manually just put values of coefficients into the set out below form.


Equation x2 + x + = 0
The result:

Discriminant D =
Roots x1 = x2 =

You can use Vieta theorem to find the roots of a quadratic equation.