My comment got autotuned/autocorrected on me, but yes. Between the proofs and the Renaissance Italians, there was also the paper from Lagrange that showed the similarities in how to get the solutions to these two equations, cubic and quartic, which is basically the start of group theory. I wanted to study complex numbers in detail but never got around to it. I mean, I know the basics, but there are a lot of neat and cool theorems you can use from them to solve real-world problems.