Higher order derivatives
Applets
Differentiation of some basic functions: Plots the first and second derivatives of a couple of standard functions (use the pull-down menu). Pull the tangent line and watch how the graphs of f' and f'' change. [MathInSite]
A first and second derivatives applet: Shows the first and second derivatives of any function you'd like. Pull the tangent line and watch how the graphs of f' and f'' change. [David Eck]
Plot three: A first and second derivative plotter. [Vanderbilt toolbox]
Online problems
Problems: Several applets ask you to match up functions with their first and second derivatives. [Maths online]