Y.S.Han Finite fields 6 Subgroups ·His said to be a subgroup of G if(i)HC G and H≠0.(i)）H is closed under the group operation of G and satisfies all the conditions of a group. Let G=(Q,+andI=(Z,+).Then II is a subgroup of G. School of Electrical Engineering Intelligentization,Dongguan University of TechnologyY. S. Han Finite fields 6 Subgroups • H is said to be a subgroup of G if (i) H ⊂ G and H ̸= ∅. (ii) H is closed under the group operation of G and satisfies all the conditions of a group. • Let G = (Q, +) and H = (Z, +). Then H is a subgroup of G. School of Electrical Engineering & Intelligentization, Dongguan University of Technology