Solution to Quadratic Equation

Theorem
The quadratic equation of the form $a x^2 + b x + c = 0$ has solutions:
 * $x = \dfrac {-b \pm \sqrt {b^2 - 4 a c} } {2 a}$

Proof
Let $a x^2 + b x + c = 0$. Then:

Also known as
This result is often referred to as the quadratic formula.