The quadratic formula is a formula capable of solving any quadratic equation of the form \( ax^2 + bx + c = 0 \). The formula is given by:
\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]
where \( a \), \( b \), and \( c \) are coefficients from the quadratic equation. This formula allows you to find the values of \( x \) that satisfy the equation, hence it can be used to find the roots or solutions of the quadratic equation.
So, the correct description from your options is: A formula capable of solving any quadratic function.