精華區beta NTU-Exam 關於我們 聯絡資訊
課程名稱︰ 代數導論一 課程性質︰ 系定必修 課程教師︰ 黃漢水教授 開課學院: 理學院 開課系所︰ 數學系 考試時間︰ 2006/11/16 12:20-15:10 是否需發放獎勵金:是 (如未明確表示,則不予發放) 試題 : 一、Suppose that α,β belong to S5 such that α = (1 2 3 4 5), β = (1 3)(4 5). Let H = <α>, K = <β>. (1) Prove or disprove that there is a positive integer k such that βα = (α^k)β (10%) (2) Prove or disprove that HK = { ab | a belongs to H, b belongs to K} is a subgroup of S5. (10%) 二、A group G has subgroups of order 8 and 20 and |G| ≦ 60. What can you conclude about |G|? (15%) 三、Suppose that G is a group, H,K are subgroups of G and a,b belong to G. Prove or disprove that if aH = bK then H = K. (20%) 四、Suppose that H is a subgroup of a group G such that (G:H) = 2. Prove that if a doesn't belong to H and b doesn't belong to H, then ab belongs to H. (15%) 五、(1) Let G be a group and an isomorphism of G onto G is called an automorphism. Prove that the set Aut(G) of all automorphisms of G is itself a group with respect to composition. (10%) (2) Let G = <α> be a cyclic group with generator α of order m. Then prove that Aut(G) is an abelian group. (10%) (3) Let G = <α> be a cyclic group with generator α of order 17. Then what is the group Aut(G). (10%) -- 讓我們擬設一些想像: 同樣星映之下處女座的我卻迷戀虛空, 迷上的月涼清語,迷上親吻繁星。 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 61.222.4.210