If quadratic equation is represented as $ax^2+bx+c = 0$, then quadratic formula is written as follows. Quadratic formula is mainly used to evaluate the roots of the quadratic equation.

Formula

$x \,=\, \dfrac{-b \pm \sqrt{b^2 -4ac}}{2a}$

Proof

Quadratic formula for quadratic equation is derived in mathematics by completing the square method.