Wikipedia often has a "History" section on these large/broad math topics. Though sometimes it requires you to be relatively familiar with the lingo to follow al

Wikipedia often has a "History" section on these large/broad math topics. Though sometimes it requires you to be relatively familiar with the lingo to follow along (See the History of Complex Numbers [1]). Specifically, for complex numbers, the problem of finding roots of polynomials is what led us there. Cubic polynomials (ones of the form ax^3 + bx^2 + cx + d) gave us the first hints of something like an imaginary unit. Even if the root is just a real number, expressing that number in terms of radicals (n-th roots) usually contains some square root of -1 that isn't eliminable. After lots of debate about the "existence" of such things, we eventually discovered the Fundamental Theorem of Algebra. For Calculus, you just need to look at Newton, Leibniz, etc. This subject was strongly motivated by physicsists trying to solve hard problems of the day. Logarithms essentially encde a relationship between addition and multiplication, something that has been recognized for quite some time! [0] [0]:https://en.wikipedia.org/wiki/History_of_logarithms https://en.wikipedia.org/wiki/History_of_logarithms [1]:https://en.wikipedia.org/wiki/Complex_number#History https://en.wikipedia.org/wiki/Complex_number#History