When $\( a \ne 0 )$, there are two solutions to $\(ax^2 + bx + c = 0)$ and they are:
$$ x = {-b \pm \sqrt{b^2-4ac} \over 2a} $$

$$
\begin{aligned}
\dot{x} & = \sigma(y-x) \
\dot{y} & = \rho x - y - xz \
\dot{z} & = -\beta z + xy
\end{aligned}
$$