1. Example `[[8,-6,2],[-6,7,-4],[2,-4,3]]` (Previous example) | 3. Example `[[1,1,1],[-1,-3,-3],[2,4,4]]` (Next example) |
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` | |
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| `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)` | |
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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` | |
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| And `A` | = | | `3` | `2` | `4` | | | `2` | `0` | `2` | | | `4` | `2` | `3` | |
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Solution is possible.
This material is intended as a summary. Use your textbook for detail explanation. Any bug, improvement, feedback then
1. Example `[[8,-6,2],[-6,7,-4],[2,-4,3]]` (Previous example) | 3. Example `[[1,1,1],[-1,-3,-3],[2,4,4]]` (Next example) |
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