Sup /sci/, look i'm an electrical engineering student, and for a while i've been taught calculus and shit, but in the end when i have to face a problem that has a strong mathematical aproximation needed, it seems that i don't have the tools to actually solve the problem, i think it's because i'm in a shithole 3rd world country and the initial courses are just being taught for the sake of it. Don't get me wrong, i have a strong foundation into solvig stuff, but when it comes to the actual understanding of what is going on that i have to solve this this or that way, i'm almost always clueless.

What i'm asking is, is there a book, o group of books that can get me a strong math foundations so i won't be a brainlet at math? I really wanna have a strong foundation before i go into complex calculus.

TL;DR: Anon studying engineering want a stronger foundation on maths, what should do?