\begin{definition}[Definition:Derivative/Higher Derivatives/Third Derivative/Notation]
The '''third derivative''' of $\map f x$ is variously denoted as:
:$\map {f'''} x$
:$\map {f^{\paren 3} } x$
:$D^3 \map f x$
:$D_{xxx} \map f x$
:$\dfrac {\d^3} {\d x^3} \map f x$
If $y = \map f x$, then it can also expressed as $y'''$:
:$y''' := \map {\dfrac \d {\d x} } {\dfrac {\d^2 y} {\d x^2} }$
and written:
:$\dfrac {\d^3 y} {\d x^3}$
\end{definition}