Thank you. I will certainly find it useful, since I am homeschooling my ten year old. He often finds educational YouTube videos but this makes it much easier to find the math we need. When I told him about it and told him the name of the site was "Kahn" Academy he said he'd rather watch lessons from a "Pro" Academy but he would try it.
I know I will find it useful because I never took trigonometry or calculus and I can get some of idea of what they are like. College algebra was as far as I went with math and it was a long time ago.
