Re: [理工] [工數]-矩陣展開

[iyenn (曉風)]

※ 引述《smallprawn (水中瑕)》之銘言：
: [ 1  2  -2]  [a11 0   0  ][1  b12 b13]
: [ -3 4  5 ] =[a21 a22 0  ][0  1   b23]
: [ 2  3  3 ]  [a31 a32 a33][0  0   1  ]
:      A      =  L            U
: 請問要如何展開求出 L、U?!
: 請高手說明了!!感謝!!

a11*1=1     =>a11=1
a11*b12=2     b12=2
a11*b13=-2    b13=-2

->
a21*1         =-3  =>a21=-3
a21*b12+a22   =4   =>a22=4- -6=10
a21*b13+a22b23=5   =>b23=(5-6)/10=-1/10

a31              =2   =>a31=2
a31b12+a32       =3   =>a32=3-4=-1
a31b13+a32b23+a33=3   =>a33=3+4-1/10=69/10

@_@y~

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