Integrated Publishing
Integrated Publishing: Maximum and Minimum Points
An explanation of how to find maximum (or minimum) point of a quadratic equation, including graphs to enhance understanding. Includes several examples/exercises, with solutions on the page.
Khan Academy
Khan Academy: Relative Maxima and Minima
Given the graph of a function, find all of its relative maximum and minimum points. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.