When watching the videos, if you have questions at any point please note the time in the video. If you simply say “You mentioned something called Izero and I don’t know what that is and can’t tell where you got it” I really don’t know whether it was for a parabola or a rectangle or what.
Please note the time in the video tape where the question arose, and the date (12/15/16?) and class (CVEN 345?) and the semester number if not this semester, so that I can quickly see exactly what you are asking about.