Definition:Derivative/Higher Derivatives/Second Derivative/Notation

Definition
The second derivative is variously denoted as:
 * $\map {f''} \xi$


 * $D^2 \map f \xi$


 * $D_{xx} \map f \xi$


 * $\map {\dfrac {\d^2} {\d x^2} } \xi$

If $y = \map f x$, then it can also expressed as $y''$:
 * $y'' := \map {\dfrac \d {\d x} } {\dfrac {\d y} {\d x} }$

and written:
 * $\dfrac {\d^2 y} {\d x^2}$

Also see

 * Definition:Differentiability Class
 * Definition:Order of Derivative