ABSTRACT
We are now ready to focus our attention on the problem of whether it is possible to solve all polynomial equations over a subfield of the complex numbers, by ordinary field arithmetic, together with the extraction of roots. We are able to do this in the quadratic case (using the quadratic formula Exercise 10.1), in the cubic case (using the Cardano-Tartaglia approach, Exercise 10.12), and in the quartic case (using the Ferrari approach, Exercise 10.20).
