作者powerkshs (气质斯文读书人)
看板Math
标题Re: [线代] rank
时间Thu Apr 7 11:34:15 2011
"=>"
Suppose not,
then
｜ a11 a12｜ ｜a11 a13｜ ｜ a12 a13｜
｜ a21 a22｜,｜a21 a23｜, ｜ a22 a23｜ is allzero
→rank(A)=0 or 1 →←
∴at least one of ｜ a11 a12｜ ｜a11 a13｜ ｜ a12 a13｜ is nonzero
｜ a21 a22｜,｜a21 a23｜, ｜ a22 a23｜
"<="
∵ at least one of ｜ a11 a12｜ ｜a11 a13｜ ｜ a12 a13｜ is nonzero
｜ a21 a22｜,｜a21 a23｜, ｜ a22 a23｜
∴rank(A)≧2
又∵矩阵Ａ是2*3
∴rank(A)≦2
∴rank(A)=2
--
※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 61.227.112.202
1F：推 calu :谢谢你:) 04/08 00:10