# Quadratic formula

In elementary algebra, the **quadratic formula** is a formula that provides the solution(s) to a quadratic equation. There are other ways of solving a quadratic equation instead of using the quadratic formula, such as factoring (direct factoring, grouping, AC method), completing the square, graphing and others.

Given a general quadratic equation of the form

whose discriminant is positive (with *x* representing an unknown, *a*, *b* and *c* representing constants with *a* ≠ 0), the quadratic formula is:

where the plus–minus symbol "±" indicates that the quadratic equation has two solutions.[1] Written separately, they become:

Each of these two solutions is also called a root (or zero) of the quadratic equation. Geometrically, these roots represent the *x*-values at which *any* parabola, explicitly given as *y* = *ax*^{2} + *bx* + *c*, crosses the *x*-axis.[2]

As well as being a formula that yields the zeros of any parabola, the quadratic formula can also be used to identify the axis of symmetry of the parabola,[3] and the number of real zeros the quadratic equation contains.[4]