4. Let G and H be isomorphic groups. Assume that every element of G has a...
III. Properties of Isomorphisms. Let G and H be isomorphic groups and suppose that 0 : G + H is an isomorphism. Assume L is a subgroup of H and define K = {g € Gº(9) EL}. Prove that K is a subgroup of G.
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),...
1. Let G - Z. Let H - {0,3,5,9) be a subgroup of (you do not need to prove this is a subgroup of G). Prove that G/l is a valid quotient group. Explain what the elements of G/H are and what the group operation is. 2. Let G be a group and H a normal subgroup in G. I E H for all IEG, then prove that G/H is abelian
Problem 3. Subgroups of quotient groups. Let G be a group and let H<G be a normal subgroup. Let K be a subgroup of G that contains H. (1) Show that there is a well-defined injective homomorphism i: K/ H G /H given by i(kH) = kH. By abuse of notation, we regard K/H as being the subgroup Imi < G/H consisting of all cosets of the form KH with k EK. (2) Show that every subgroup of G/H is...
Let G be a group and let H,K be normal subgroups of G such that H∩K = {e} and that G = {hk|h ∈ H,k ∈ K}. (1)Prove that for every h∈H, k∈K we have kh(k^-1)(h^−1) = e in G. (2) Prove that the group G is isomorphic to H × K. Hint: For (2), consider the map φ : H ×K → G, defined as φ(h,k) = hk, whereh ∈ H,k ∈ K.
Always give rigorous arguments I. (A) Let G be a group under * and let g E G with o(g) = n (finite) (i) Show that g can never go back to any previous positive power of g* (1k< n) when taking up to the nth power (cf. g), e., that there are no integers k and m such that 1< k<m<n and such that g*-gm (ii) How many elements of the set (e, g,g2.... .g"-) are actually distinct? (iii)...
5) Leth-{ơes,lo(4) 4) That is, H is the set of permutation in S4 that leave the element 4 in its place. (i) Prove that H is a subgroup of S4. (ii) Prove that S is isomorphic to H. Explicitly give an isomorphism f: S3 → H listing the 6 elements of S, and giving the permutation in H to which it is sent under f. (ii) 1S "Spot check" the homomorphism property by showing that 5) Leth-{ơes,lo(4) 4) That is,...
Theorem 7.5 Let G be a group. (1) G has a unique identity element (2) Cancellation Laws. For all a, b,ce G, if ab ac, then b-c. For all a, b,c E G, if ba-ca, then (3) Each element of G has a unique inverse: For each a E G, there exists a unique element d e G such that ad-e and da e . Prove that each element of a finite group G appears exactly once in each row...
Definition. Let G be a group and let a € G. The centralizer of a is C(a) = {9 € G ag = ga}, i.e. it consists of all elements in G that commute with a. (18) (a) In the group Zui, find C(3). (b) Complete and prove the following: If G is an Abelian group and a EG, then C(a) = _. (c) Prove or disprove: In every group G, there exists a E G such that C(a) =...
4 Let G be an unknown group of order 8. By the First Sylow Theorem, G must contain a subgroup H of order 4 (a) If all subgroups of G of order 4 are isomorphic to V then what group must G be? Completely justify your answer. (b) Next, suppose that G has a subgroup H one of the following C Then G has a Cayley diagram like Find all possibilities for finishing the Cayley diagram. (c) Label each completed...