Hello.  I am starting the Parabolas / Quadratic functions in Algebra 1 section (the last full section, yeah!).  There is only one video that Sal has done and it does not cover any math, but the questions asked seem to think he has.  I have submitted 2 reports through the questions and will add another post here.  Sal needs to do at least one more math of parabolas video, please.  Until then, please update the questions by removing the math-required ones and make other ones (love the interactive widget!).  Thank you!