Near the end of the lesson, one of my students asks a question about why the values start turning around 0.4 - I made a couple of videos that explain this phenomenon: https://www.youtube.com/watch?v=cDbnPaeZgQ0 (Part 1) and https://www.youtube.com/watch?v=a0ePXSvQuaQ (Part 2) Main site: http://www.misterwootube.com/ Second channel (for teachers): null Connect with me on Twitter (http://twitter.com/misterwootube) or Facebook (http://fb.com/misterwootube)