@SimplyBeautifulArt Then do try Graph or Geogebra. Graph can easily do recursive definitions because it has a ternary conditional operator and custom definable functions!
It's not my software, but I've been using it for years for plotting graphs, though I use Geogebra for geometry.
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Well, about books, you shouldn't worry about it because you can download them from some webpages. I do that because in my country is impossible to find that kind of books
Yes, there are some online courses in MIT, Harvard for example
It isn't a full text, but it's a good place to start. I'll search my other "favorites/bookmarks" (but I have well over a thousand such favorites and bookmarks, some organized, but too many still left in the "general bookmarks" which haven't yet been sorted.
Most math books I have seen seem to be structured in the same way; each chapter is a few dozen pages, and after each chapter there are a few dozen exercises. I often find myself not knowing what exercises to do and when to do them. If I have read the first 10 pages, I'm not sure what $x$ is in "t...