derivative
\[\frac{d}{d x} (f(x) g(x) h(x))
= f'(x) g(x) h(x)
+ f(x) g'(x) h(x)
+ f(x) g(x) h'(x)\]
\[\begin{eqnarray*}
\begin{array}{rclcccc}
\frac{d^{2}}{d x^{2}} (f(x) g(x) h(x))
& = & & f''(x) g(x) h(x) & + & f'(x) g'(x) h(x) & + & f'(x) g(x) h'(x)
\\
& & + & f'(x) g'(x) h(x) & + & f(x) g''(x) h(x) & + & f(x) g'(x) h'(x)
\\
& & + & f'(x) g(x) h'(x) & + & f(x) g'(x) h'(x) & + & f(x) g(x) h''(x)
\\
& = & & f''(x) g(x) h(x) & + & f(x) g''(x) h(x) & + & f(x) g(x) h''(x)
\\
& & + & 2f'(x) g'(x) h(x) & + & 2f'(x) g(x) h'(x) & + & 2f(x) g'(x) h'(x)
\end{array}
\end{eqnarray*}\]