I have recently started getting back into mathematics as a consequence of trying to get a better grasp on machine learning. I started studying from a machine learning book but found the language extremely convoluted and abstruse. Fortunately, the book referenced Gilbert Strang's book on linear algebra.
Now, I wish to get back into mathematics, gain a better understanding and possibly a degree somewhere down the line. So, I am trying to relearn linear algebra and calculus (for now). I was trying to find some books for study and a lot of people recommended Micheal Spivak's Calculus which I managed to get a copy.
Now, here's my dilemma. From what I can recollect about studying calculus in school is that there were a lot of topics (general equations for circles, parabolas, hyperbola; limits and continuity, trigonometry, arithmetic geometric harmonic progression, complex numbers etc), that were taught before starting calculus. Spivak's book does have limits and continuity (about 50 pages) as a topic but I was skeptical about how much it could actually cover so I found Introduction to Real Analysis as a sort of precursor book to read before reading Spivk's Calculus. The first 6 chapters and chapter 9 (infinite series) of this book are familiar to me based on previous coursework.
Now my main question is should I first study limits and functions from this book before moving onto Spivak's calculus or will Spivak's calculus suffice? I am trying to rebuild a string foundation so I am looking for books with in-depth explanations (I like how Prof. Strang's book discusses concepts with the reader)
I would also appreciate advice regarding purchase of a single pre-calculus book that covers all topics or different pre-calculus books for each separate topic. I think rigorously practicing each topic would be best.
Thank you.