Thanks for that link to U Tube. Now I understand your difficulty.
Teacher's advice to Khan academy:
(1) Make sure your mic volume is set correctly. Even on 100% volume I could barely hear the speaker.
(2) Plan your 'board' layout in advance so you don't have wobbly lines and have to rub out bits because they won't fit.
(3) Use different colours but only those that have a decent contrast with the black background. Yellow is excellent; purple is very poor and barely readable. Have printed text not handwritten notes so that we don't have to struggle reading your writing.
Sorry 666 bro but I felt I needed to get that off my chest. No wonder you are struggling with this. It's great that the Academy do this for free but they could learn a lot from MIF. I suggest you look instead at this page:
https://www.mathsisfun.com/calculus/limits-formal.html
Compare the two and you'll see why I think MIF is such a brilliant resource.
Hope that helps,
Bob
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