Waardenverloop
Illustrates various graph characteristics such as function values, extrema, increase/decrease, and concavity.
Drag the purple dots around the display to change the graph. Drag the "a" and "b" dots left and right to change the interval of interest. Check the boxes one at a time to illustrate the concept described. (You can have more than one box checked, but the display might get confusing with too much going on at once!)
Relative (Local) and Absolute (Global) extrema (min/max) are valid on the closed interval [a, b].
Selecting "x & y Cursors" allows you to drag the blue "x" dot along the x-axis, and see the corresponding y-value projected onto the y-axis.