1. Adjoint method example
( Enter your problem )
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- Example `[[3,1,1],[-1,2,1],[1,1,1]]`
- Example `[[2,3,1],[0,5,6],[1,1,2]]`
- Example `[[2,3],[4,10]]`
- Example `[[5,1],[4,2]]`
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Other related methods
- Adjoint method
- Gauss-Jordan Elimination method
- Cayley Hamilton method
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1. Example `[[3,1,1],[-1,2,1],[1,1,1]]`
1. Find Inverse of matrix `A=[[3,1,1],[-1,2,1],[1,1,1]]`
Solution:
`|A|` | = | | `3` | `1` | `1` | | | `-1` | `2` | `1` | | | `1` | `1` | `1` | |
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`=3 xx (2 × 1 - 1 × 1) -1 xx (-1 × 1 - 1 × 1) +1 xx (-1 × 1 - 2 × 1)`
`=3 xx (2 -1) -1 xx (-1 -1) +1 xx (-1 -2)`
`=3 xx (1) - -1 xx (-2) +1 xx (-3)`
`= 3 +2 -3`
`=2`
`Adj(A)` | = | Adj | | `3` | `1` | `1` | | | `-1` | `2` | `1` | | | `1` | `1` | `1` | |
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= | | `+(2 × 1 - 1 × 1)` | `-(-1 × 1 - 1 × 1)` | `+(-1 × 1 - 2 × 1)` | | | `-(1 × 1 - 1 × 1)` | `+(3 × 1 - 1 × 1)` | `-(3 × 1 - 1 × 1)` | | | `+(1 × 1 - 1 × 2)` | `-(3 × 1 - 1 × (-1))` | `+(3 × 2 - 1 × (-1))` | |
| T |
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= | | `+(2 -1)` | `-(-1 -1)` | `+(-1 -2)` | | | `-(1 -1)` | `+(3 -1)` | `-(3 -1)` | | | `+(1 -2)` | `-(3 +1)` | `+(6 +1)` | |
| T |
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= | | `1` | `2` | `-3` | | | `0` | `2` | `-2` | | | `-1` | `-4` | `7` | |
| T |
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= | | `1` | `0` | `-1` | | | `2` | `2` | `-4` | | | `-3` | `-2` | `7` | |
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`"Now, "A^(-1)=1/|A| × Adj(A)`
= | `1/(2)` × | | `1` | `0` | `-1` | | | `2` | `2` | `-4` | | | `-3` | `-2` | `7` | |
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= | | `1/2` | `0` | `-1/2` | | | `1` | `1` | `-2` | | | `-3/2` | `-1` | `7/2` | |
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This material is intended as a summary. Use your textbook for detail explanation. Any bug, improvement, feedback then
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