(5) Let G be a group, and let H be a subgroup of G. Define a relation ~ on G as follows: X~ · y if x-ly E H. Prove that this is an equivalence relation, and that the equivalence classes of the relation are the left cosets of H.
4 (a) Let G be an abelian group with identity e and let H- gEGI8-e. Prove that H is a subgroup of G 4 (a) Let G be an abelian group with identity e and let H- gEGI8-e. Prove that H is a subgroup of G
(8) Let G be a group and let H be a subgroup of G. Prove that the right cosets of H partition G, that is, G= U Hy HYEH\G and, if y, y' E G and Hyn Hy' + 0, then Hy= Hy'.
Let Ha normal subgroup of a finite group Gwith m G H prove that g' E Hfor all g E G. What happens if H isn't normal? Let Ha normal subgroup of a finite group Gwith m G H prove that g' E Hfor all g E G. What happens if H isn't normal?
7. Let G be a group and let H be a subgroup of G. Prove that the relationon G given by ab if ab-i є H is an equivalence relation.
Let G be a finite group and let H be a subgroup of G. Show using double cosets that there is a subset T of G which is simultaneously a left transversal for H and a right transversal for H.
2. problem 3. Let H be a normal subgroup of a group G and let K be any subgroup of G. Prove that the subset HK of G defined by is a subgroup of G Let G S, H ), (12) (34), (13) (24), (1 4) (23)J, and K ((13)). We know that H is a normal subgroup of S, so HK is a subgroup of S4 by Problem 2. (a) Calculate HK (b) To which familiar group is HK...
Let G be a finite group with subgroup H. Define E = { g^{-1} H g : g \in G }. Prove that |E| divides |G/H|.
11. Prove that a nonempty subset H of a group G is a subgroup of G if and only if whenever a, b E H, then ab-1 e H
3. a. Let H be a subgroup of a commutative group G. If every element h ∈ H is a square in H (i.e., h = k 2 for some k ∈ H), and every element of G/H is a square in G/H, then every element of G is a square in G. b. Let G be a group and H a subgroup with [G : H] = 2. If g ∈ G has odd order (i.e., ord(g) is odd),...