Let F be a field.
((a)) Prove that the field of fractions of F[x], denoted by F(x), is isomorphic to the set of all rational expressions p(x)/q(x), where q(x) is not the zero polynomial.
((b)) Let p(x1,…,xn) and q(x1,…,xn) be polynomials in F[x1,…,xn]. Show that the set of all rational expressions p(x1,…,xn)/q(x1,…,xn) is isomorphic to the field of fractions of F[x1,…,xn]. We denote the field of fractions of F[x1,…,xn] by F(x1,…,xn).