ABSTRACT

Chapter 23. A djoining Roots to Polynomials: Splitting Fields

In the previous sections we studied algebraic elements in terms of the poly­ nomials that they satisfy. Now we reverse the question and ask, how can we determine the roots of a polynomial? This question has several possible in­ terpretations, and there exists a highly developed theory of approximating roots of a polynomial in a given field. However, we are interested in an ex­ act algebraic solution, and thus our first interpretation is, “Given / E F[x], can we find a field K that contains all the roots of / ? ” First we locate one root. To understand the question, let us examine a familiar situation.