Help calculating a math limit Can anyone help with this limit?
\begin{equation*}
\lim_{x \rightarrow 4}
\frac{16\sqrt{x-\sqrt{x}}-3\sqrt{2}x-4\sqrt{2}}{16(x-4)^2}
\end{equation*}
I've tried a variable change of  \begin{equation*} y=\sqrt{x} \end{equation*} but this didn't help.

Hint:
Set $x=4+h\;(h\to 0)$ and apply repeatedly Taylor's formula at order $2$.
