subfield

noun subfields

1. A smaller, more specialized area of study or occupation within a larger one
2. A subring of a field, containing the multiplicative identity and closed under inversion. Let us describe in general the subfield generated by a given element. Let K be a given field, F a subfield of K, and c an element of K. Consider those elements of K which are given by polynomial expressions of the form (1)#92;qquadf(c)#61;a#95;0#43;a#95;1c#43;a#95;2c²#43;...#43;a#95;ncⁿ#92;qquad#92;