Definition:Derivative/Higher Derivatives/Second Derivative/Notation

Definition
The second derivative is variously denoted as:
 * $f'' \left({\xi}\right)$


 * $D^2 f \left({\xi}\right)$


 * $D_{xx} f \left({\xi}\right)$


 * $\dfrac{\mathrm d^2}{\mathrm d x^2} \left({\xi}\right)$

If $y = f \left({x}\right)$, then it can also expressed as $y''$:
 * $y'' := \dfrac {\mathrm d} {\mathrm d x} \left({\dfrac {\mathrm d y} {\mathrm d x}}\right)$

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

Also see

 * Definition:Differentiability Class
 * Definition:Order of Derivative