Solution (source code)

= Solution

The positive horizontal coordinate is $x=\sqrt{3/2}=\sqrt6/2$. By <implicit differentiation>,
$$
2y\frac{dy}{dx}+4x=0,
\qquad \frac{dy}{dx}=-\frac{2x}{y}.
$$
At the selected point this gives \b[$dy/dx=-\sqrt6$].