[理工] [線代]-六題證明題,請大家幫幫忙!

看板Grad-ProbAsk作者 (阿年:))時間16年前 (2009/10/28 21:01), 編輯推噓0(007)
留言7則, 2人參與, 最新討論串1/1
1.Is the transpose of an elementary matrix an elementary matrix of the same type? Is the product of two elementary matrices an elementary matrix? 2.Let A be a 3x3 matrix and suppose that a1=3a2-2a3 Will the system Ax=0 have a nontrivial solution? Is A nonsingular? 3.Let A and B be nxn matrices and let C=A-B. Show that if Ax0=Bx0 and x0≠0,then C must be singular. 4.Let A and B be nxn matrices and let C=AB. Prove that if B is singular then C must be singular. 5.Show that if A is a symmetric nonsingular matrix,then A^-1 is also symmetric 6.Prove that if A is row equivalent to B,then B is row equivalent to A. -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 210.240.186.200

10/28 21:03, , 1F
作業嗎?= =y
10/28 21:03, 1F

10/28 21:14, , 2F
意思意思來個算一兩題... 4.det(B)=0 ->det(C)=det(A)det(B)
10/28 21:14, 2F

10/28 21:14, , 3F
C is singular.
10/28 21:14, 3F

10/28 21:15, , 4F
3. (A-B)x=0=Cx -> x=/=0 ->C is singular.
10/28 21:15, 4F

10/28 21:17, , 5F
5. A^T=A, (A^-1)^T=(A^T)^-1=A^-1 A^-1 is symmetric
10/28 21:17, 5F

10/28 21:19, , 6F
6.E1E2...EkA=B Ek^-1...E2^-1E1^-1B=A 這樣?,應該吧XD
10/28 21:19, 6F

10/28 21:36, , 7F
→謝謝你喔︿︿
10/28 21:36, 7F
文章代碼(AID): #1Aw42Sjq (Grad-ProbAsk)