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10. LU decomposition using Crout's method of matrix example ( Enter your problem )
  1. Example `[[8,-6,2],[-6,7,-4],[2,-4,3]]`
  2. Example `[[3,2,4],[2,0,2],[4,2,3]]`
  3. Example `[[1,1,1],[-1,-3,-3],[2,4,4]]`
  4. Example `[[2,3],[4,10]]`

2. Example `[[3,2,4],[2,0,2],[4,2,3]]`





Find LU decomposition using Crout's method of Matrix ...
`[[3,2,4],[2,0,2],[4,2,3]]`


Solution:
Crout's method for LU decomposition
Let `A=LU`

`3``2``4`
`2``0``2`
`4``2``3`
 = 
`l_(11)``0``0`
`l_(21)``l_(22)``0`
`l_(31)``l_(32)``l_(33)`
 `xx` 
`1``u_(12)``u_(13)`
`0``1``u_(23)`
`0``0``1`


`3``2``4`
`2``0``2`
`4``2``3`
 = 
`l_(11)``l_(11)u_(12)``l_(11)u_(13)`
`l_(21)``l_(21)u_(12) + l_(22)``l_(21)u_(13) + l_(22)u_(23)`
`l_(31)``l_(31)u_(12) + l_(32)``l_(31)u_(13) + l_(32)u_(23) + l_(33)`


This implies
`l_(11)=3`

`l_(11)u_(12)=2=>3xxu_(12)=2=>u_(12)=0.6666666667`

`l_(11)u_(13)=4=>3xxu_(13)=4=>u_(13)=1.3333333333`



`l_(21)=2`

`l_(21)u_(12) + l_(22)=0=>2xx0.6666666667 + l_(22)=0=>l_(22)=-1.3333333333`

`l_(21)u_(13) + l_(22)u_(23)=2=>2xx1.3333333333 + (-1.3333333333)xxu_(23)=2=>u_(23)=0.5`



`l_(31)=4`

`l_(31)u_(12) + l_(32)=2=>4xx0.6666666667 + l_(32)=2=>l_(32)=-0.6666666667`

`l_(31)u_(13) + l_(32)u_(23) + l_(33)=3=>4xx1.3333333333 + (-0.6666666667)xx0.5 + l_(33)=3=>l_(33)=-2`



Now checking `A=LU` ?

`LU` = 
`3``0``0`
`2``-1.3333333333``0`
`4``-0.6666666667``-2`
 `xx` 
`1``0.6666666667``1.3333333333`
`0``1``0.5`
`0``0``1`
 = 
`3``2``4`
`2``0``2`
`4``2``3`


And `A` = 
`3``2``4`
`2``0``2`
`4``2``3`


Solution is possible.




This material is intended as a summary. Use your textbook for detail explanation.
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