Let a and b be elements of a group with identity 1. Suppose a and b...
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> .
2.1.3. Prove the following refinement of the uniqueness of the identity in a group: Let G be a group with identity element e, and let e', g E G. Suppose e' and g are elements of G. If e'g says that if a group element acts like the identity when multiplied by one element on one side, then it is the identity.) -g, then e, e. (This result
1-5 theorem, state it. Define all terms, e.g., a cyclic group is generated by a single use a element. T encourage you to work together. If you find any errors, correct them and work the problem 1. Let G be the group of nonzero complex numbers under multiplication and let H-(x e G 1. (Recall that la + bil-b.) Give a geometric description of the cosets of H. Suppose K is a proper subgroup of H is a proper subgroup...
(4) Let p Z be a prime. Prove that zli/(p+1) has exactly ] p2 +1 elements. Use that 5+5i (2+i)(3+i) to determine how many elements Zu/5+5i) has. (5) Let m,n be integers with m|n. Prove that the surjective ring homomor- phism Z/n -> Z/m induces a group homomorphism on units, and that this group homomorphism is also surjective. (4) Let p Z be a prime. Prove that zli/(p+1) has exactly ] p2 +1 elements. Use that 5+5i (2+i)(3+i) to determine...
Please show all steps clearly. 4. (a) Define when two elements of a group are conjugate to each other. State and de- duce the class equation using the decomposition of a group in conjugacy classes (b) Let G be a finite group and p a prime number such that p divides G. Prove that there is a subgroup H of G such that |H p. (c) Let p be a prime number. Prove that any positive integer n, any group...
1. Let a and b be elements of a group . Prove that ab and ba have the same order. 2. Show by example that the product of elements of nite order in a group need not have nite order. What if the group is abelian?
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...
(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
#2. Let n E N and X1,X2, ,yn, and zi,22, An be real numbers. ,An, yī,Y2, #a) Prove the identity #b) Use the identity in #a) to prove (the Cauchy-Schwartz inequality) that #1) Extend the result in #b) to prove that #d) Use the inequality in #b) to prove the inequality which is the triangle inequality #2. Let n E N and X1,X2, ,yn, and zi,22, An be real numbers. ,An, yī,Y2, #a) Prove the identity #b) Use the identity...
(1) Let p be a prime number. Describe all the groups with p elements. (2) Let # be a permutation in S(4). What are the possible orders of T according to Lagrange's theorem? (3) Show that there are no elements of order 8 in S(4) (even though 8 divides 24 = 4!).