When $a \ne 0$, there are two solutions to $(ax^2 + bx + c = 0)$ and they are $$ x = {-b \pm \sqrt{b^2-4ac} \over 2a} $$ $$ \sum_{i=0}^n{x^{-2} \over DL_i} \times 2^{-\frac{1}{2}} $$ $$ \sqrt[3]{\sum_{i=1}^{\infty}} $$ $$\frac{\Delta x}{\Delta t}$$
