Re: [線代] 請教3個反矩陣相乘公式

看板Math作者 (阿翔)時間13年前 (2012/06/19 19:49), 編輯推噓1(1011)
留言12則, 3人參與, 最新討論串3/3 (看更多)
※ 引述《mack (腦海裡依然記得妳)》之銘言: : ※ 引述《Mopack22926 (阿翔)》之銘言: : : http://upload.lsforum.net/users/public/w1372f371756577-mg3.jpg
: : 請教A與?的算法 謝謝 : -1 1 : [a b] = -----[ d -b] : [c d] ad-bc[-c a] : -1 1 : [S+1 -1] = ----------[S+1 1] : [0 S+1] (S+1)(S+1)[0 S+1] : 1 : 所求=[2 0]*----------[S+1 1]*[0] : (S+1)(S+1)[0 S+1] [1] : 1 : =----------[2 0][S+1 1][0] : (S+1)(S+1) [0 S+1][1] : 2 : =---------- : (S+1)(S+1) http://upload.lsforum.net/users/public/w5146211t3.jpg
小弟照矩陣公式..求算不出2.. 請教一下三階這邊怎麼計算.. -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 59.104.85.3

06/19 19:51, , 1F
因為你弄錯矩陣乘法了...
06/19 19:51, 1F

06/19 19:53, , 2F
請問一下...這三個怎麼相乘變成2...
06/19 19:53, 2F

06/19 19:54, , 3F
[2 0][S+1 1 ] = [2x(S+1)+0x0 2x1+0x(S+1)] = [
06/19 19:54, 3F

06/19 19:54, , 4F
[0 S+1]
06/19 19:54, 4F

06/19 19:54, , 5F
然後
06/19 19:54, 5F

06/19 19:54, , 6F
[2(S+1) 2][0] = [2(S+1)x0+2x1] = [2]
06/19 19:54, 6F

06/19 19:54, , 7F
[1]
06/19 19:54, 7F

06/19 19:55, , 8F
...第一行被切掉了 結果是第二段的開頭那一個
06/19 19:55, 8F

06/19 20:00, , 9F
了解了...難怪我越乘越多階..
06/19 20:00, 9F

06/19 20:00, , 10F
謝謝解答!
06/19 20:00, 10F

08/13 16:56, , 11F
08/13 16:56, 11F

09/17 14:52, , 12F
因為你弄錯矩陣乘法了. https://daxiv.com
09/17 14:52, 12F
文章代碼(AID): #1Fu6TMPq (Math)
文章代碼(AID): #1Fu6TMPq (Math)