V. More Orders. Let a,b,c be elements of a group G. (i). If ord(a)= 15, what...
(iii). Assume G is abelian. If ord(a)= 15 and ord(c)= 5, what can ord(ac) equal?
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)...
Question 4 a) If a group G has order 323, what are the possible orders of its proper b) Let G<a > be a cyclic group of order 10. Is the map f: G-> G define«d subgroups: by Зі i. f(a) - a and f(a')-a agroup isomorphism? ii(a) and fa a a group isomorphism? 12, 5, 5
3. Let G be a group containing 6 elements a, b, c, d, e, and f. Under the group operation called the multiplication, we know that ad = c, bd = f, and f2 = bc = e. We showed you in class that the identity is e, hence the e-row and e-column were revealed. Using associativity, we also found cb, cf, af, and a2. Now try to imitate the idea and find five more entries. Justify your answer. Hint:...
Let a and b be elements of a group G such that b has order 2 and
ab=ba^-1
12. Let a and b be elements of a group G such that b has order 2 and ab = ba-1. (a) Show that a” b = ba-n for all integers n. Hint: Evaluate the product (bab)(bab) in two different ways to show that ba+b = a-2, and then extend this method. (b) Show that the set S = {a”, ba" |...
4) Let G be a group and let a є G. The centralizer of a in G is defined as the set (i) Show that Ca(a) is a subgroup of G (ii) Find the centralizers of the elements r and y in the Dihedral group D4
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> .
Problem 4. Let G be a group. Recall that the order of an element g G is the smallest k such that gk = 1 (or 00, if such a k doesn't exist). (a) Find the order of each element of the symmetric group S (b) Let σ-(135)(24) and τ-(15)(23)(4) be permutations in S5. Find the cycle decompositions for (c) Let σ-(123456789). Compute ơ-i, σ3, σ-50, and σί006 (d) Find all numbers n such that Ss contains an element of...
Let G be a group of order 6 and let X be the set (a, b,c) E G3: abc That is, X is the set of triples of elements of G with the product of its coordinates equals the identity element of G (a) How many elements does X have? Hint: Every triple (a, b, c) in X is completely determined by the choice of a and b. Because once you choose a and b then c must be (ab)-1...
Let G be a group, and let a ∈ G. Let φa : G −→ G be defined by
φa(g) = aga−1 for all g ∈ G. (a) Prove that φa is an automorphism
of G. (b) Let b ∈ G. What is the image of the element ba under the
automorphism φa? (c) Why does this imply that |ab| = |ba| for all
elements a, b ∈ G?
9. (5 points each) Let G be a group, and let...