Let
Want to see the full answer?
Check out a sample textbook solutionChapter 6 Solutions
Contemporary Abstract Algebra
- Exercises 18. Suppose and let be defined by . Prove or disprove that is an automorphism of the additive group .arrow_forwardExercises 35. Prove that any two groups of order are isomorphic.arrow_forward16. Suppose that is an abelian group with respect to addition, with identity element Define a multiplication in by for all . Show that forms a ring with respect to these operations.arrow_forward
- Let G=1,i,1,i under multiplication, and let G=4=[ 0 ],[ 1 ],[ 2 ],[ 3 ] under addition. Find an isomorphism from G to G that is different from the one given in Example 5 of this section. Example 5 Consider G=1,i,1,i under multiplication and G=4=[ 0 ],[ 1 ],[ 2 ],[ 3 ] under addition. In order to define a mapping :G4 that is an isomorphism, one requirement is that must map the identity element 1 of G to the identity element [ 0 ] of 4 (part a of Theorem 3.30). Thus (1)=[ 0 ]. Another requirement is that inverses must map onto inverses (part b of Theorem 3.30). That is, if we take (i)=[ 1 ] then (i1)=((i))1=[ 1 ] Or (i)=[ 3 ] The remaining elements 1 in G and [ 2 ] in 4 are their own inverses, so we take (1)=[ 2 ]. Thus the mapping :G4 defined by (1)=[ 0 ], (i)=[ 1 ], (1)=[ 2 ], (i)=[ 3 ]arrow_forwardExamples 5 and 6 of Section 5.1 showed that P(U) is a commutative ring with unity. In Exercises 4 and 5, let U={a,b}. Is P(U) a field? If not, find all nonzero elements that do not have multiplicative inverses. [Type here][Type here]arrow_forwardExercises 8. Find an isomorphism from the group in Example of this section to the multiplicative group . Sec. 16. Prove that each of the following sets is a subgroup of , the general linear group of order over .arrow_forward
- 11. Show that defined by is not a homomorphism.arrow_forwardProve part c of Theorem 3.4. Theorem 3.4: Properties of Group Elements Let G be a group with respect to a binary operation that is written as multiplication. The identity element e in G is unique. For each xG, the inverse x1 in G is unique. For each xG,(x1)1=x. Reverse order law: For any x and y in G, (xy)1=y1x1. Cancellation laws: If a,x, and y are in G, then either of the equations ax=ay or xa=ya implies that x=y.arrow_forwardLet H and K be arbitrary groups and let HK denotes the Cartesian product of H and K: HK=(h,k)hHandkK Equality in HK is defined by (h,k)=(h,k) if and only if h=h and k=k. Multiplication in HK is defined by (h1,k1)(h2,k2)=(h1h2,k1k2). Prove that HK is a group. This group is called the external direct product of H and K. Suppose that e1 and e2 are the identity elements of H and K, respectively. Show that H=(h,e2)hH is a normal subgroup of HK that is isomorphic to H and, similarly, that K=(e1,k)kK is a normal subgroup isomorphic to K. Prove that HK/H is isomorphic to K and that HK/K is isomorphic to H.arrow_forward
- Elements Of Modern AlgebraAlgebraISBN:9781285463230Author:Gilbert, Linda, JimmiePublisher:Cengage Learning,Linear Algebra: A Modern IntroductionAlgebraISBN:9781285463247Author:David PoolePublisher:Cengage Learning