6. Suppose G = {21, 22, ...,an} is an abelian group with G = n. (a)...
22 Must the center of a group be Abelian? 23. Let G be an Abelian group with identity e and let n be some integer Prove that the set of all élements of G that satisfy the equation* - e is a subgroup of G. Give an example of a group G in which the set of all elements of G that satisfy the equation :2 -e does not form a subgroup of G. (This exercise is referred to in...
Let Ga finite abelian group. Prove that a)If pa primenumber divides G|, G has an element of order p b)If G2n with n odd, G has exactly oneelement with order 2 Let Ga finite abelian group. Prove that a)If pa primenumber divides G|, G has an element of order p b)If G2n with n odd, G has exactly oneelement with order 2
2. Let G be an abelian group. Suppose that a and b are elements of G of finite order and that the order of a is relatively prime to the order of b. Prove that <a>n<b>= <1> and <a, b> = <ab> .
Abstract algebra A. Assume G is an abelian group. Let n > 0 be an integer. Prove that f(x) = ?" is a homomorphism from Got G. B. Assume G is an abelian group. Prove that f(x) = 2-1 is a homomorphism from Got G. C. For the (non-abelian) group S3, is f(x) = --! a homomorphism? Why?
Give a counterexample to prove the following conjectures false, 21. All mammals live on land. 22. If a number is even, then it is a multiple of four. 23. A number is only divisible by five, if the number ends in five. 24. Two odd numbers will have a sum that is odd. 25. All four-sided polygons have four right angles.
(3) (7 points) Let G be a finite abelian group of order n. Let k be relatively prime to n. Prove the map : G G given by pla) = ak is an automor- phism of G
16. Prove that if G is a cyclic group then G is abelian.
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
9) A group G is called solvable if there is a sequence of subgroups such that each quotient Gi/Gi-1 is abelian. Here Gi-1 Gi means Gi-1 is a normal subgroup of Gi. For example, any abelian group is solvable: If G s abelian, take Go f1), Gi- G. Then G1/Go G is abelian and hence G is solvable (a) Show that S3 is solvable Suggestion: Let Go- [l),Gı-(123)), and G2 -G. Here (123)) is the subgroup generated by the 3-cycle...
5. Let N be a normal subgroup of a group G and G/N be the quotient group of all right cosets of N in G. Prove each of the following: (a) (2 pts) If G is cyclic, then so is G/N. (b) (3 pts) G/N is Abelian if and only if aba-16-? E N Va, b E G. (c) (3 pts) If G is a finite group, then o(Na) in G/N is a divisor of (a) VA EG.