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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]]`

3. Example `[[1,1,1],[-1,-3,-3],[2,4,4]]`





Find LU decomposition using Crout's method of Matrix ...
`[[1,1,1],[-1,-3,-3],[2,4,4]]`


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

`1``1``1`
`-1``-3``-3`
`2``4``4`
 = 
`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`


`1``1``1`
`-1``-3``-3`
`2``4``4`
 = 
`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)=1`

`l_(11)u_(12)=1=>1xxu_(12)=1=>u_(12)=1`

`l_(11)u_(13)=1=>1xxu_(13)=1=>u_(13)=1`



`l_(21)=-1`

`l_(21)u_(12) + l_(22)=-3=>(-1)xx1 + l_(22)=-3=>l_(22)=-2`

`l_(21)u_(13) + l_(22)u_(23)=-3=>(-1)xx1 + (-2)xxu_(23)=-3=>u_(23)=1`



`l_(31)=2`

`l_(31)u_(12) + l_(32)=4=>2xx1 + l_(32)=4=>l_(32)=2`

`l_(31)u_(13) + l_(32)u_(23) + l_(33)=4=>2xx1 + 2xx1 + l_(33)=4=>l_(33)=0`



Now checking `A=LU` ?

`LU` = 
`1``0``0`
`-1``-2``0`
`2``2``0`
 `xx` 
`1``1``1`
`0``1``1`
`0``0``1`
 = 
`1``1``1`
`-1``-3``-3`
`2``4``4`


And `A` = 
`1``1``1`
`-1``-3``-3`
`2``4``4`


Solution is possible.




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