1. Find `"Minor"(A)` ...
`A=[[1,2],[4,5]]`
Solution:
`A_(11)=`minor of `1=` | | `=5` | `=5` |
`A_(12)=`minor of `2=` | | `=4` | `=4` |
`A_(21)=`minor of `4=` | | `=2` | `=2` |
`A_(22)=`minor of `5=` | | `=1` | `=1` |
The minor matrix of A is `[A_(ij)]` | = | | `A_(11)` | `A_(12)` | | | `A_(21)` | `A_(22)` | |
| = | |
Method-2 : all minors in matrix form
2. Find `"Minor"(A)` ...
`A=[[1,2,3],[4,5,6],[7,8,9]]`
Solution:
`MINOR(A)` | = | `MINOR` | | `1` | `2` | `3` | | | `4` | `5` | `6` | | | `7` | `8` | `9` | |
|
|
`A_(11)=`minor of `1=` | | `=5 × 9 - 6 × 8` | `=45 -48` | `=-3` |
`A_(12)=`minor of `2=` | | `=4 × 9 - 6 × 7` | `=36 -42` | `=-6` |
`A_(13)=`minor of `3=` | | `=4 × 8 - 5 × 7` | `=32 -35` | `=-3` |
`A_(21)=`minor of `4=` | | `=2 × 9 - 3 × 8` | `=18 -24` | `=-6` |
`A_(22)=`minor of `5=` | | `=1 × 9 - 3 × 7` | `=9 -21` | `=-12` |
`A_(23)=`minor of `6=` | | `=1 × 8 - 2 × 7` | `=8 -14` | `=-6` |
`A_(31)=`minor of `7=` | | `=2 × 6 - 3 × 5` | `=12 -15` | `=-3` |
`A_(32)=`minor of `8=` | | `=1 × 6 - 3 × 4` | `=6 -12` | `=-6` |
`A_(33)=`minor of `9=` | | `=1 × 5 - 2 × 4` | `=5 -8` | `=-3` |
The minor matrix of A is `[A_(ij)]` | = | | `A_(11)` | `A_(12)` | `A_(13)` | | | `A_(21)` | `A_(22)` | `A_(23)` | | | `A_(31)` | `A_(32)` | `A_(33)` | |
| = | | `-3` | `-6` | `-3` | | | `-6` | `-12` | `-6` | | | `-3` | `-6` | `-3` | |
|
Method-2 : all minors in matrix form
= | | `5 × 9 - 6 × 8` | `4 × 9 - 6 × 7` | `4 × 8 - 5 × 7` | | | `2 × 9 - 3 × 8` | `1 × 9 - 3 × 7` | `1 × 8 - 2 × 7` | | | `2 × 6 - 3 × 5` | `1 × 6 - 3 × 4` | `1 × 5 - 2 × 4` | |
|
= | | `45 -48` | `36 -42` | `32 -35` | | | `18 -24` | `9 -21` | `8 -14` | | | `12 -15` | `6 -12` | `5 -8` | |
|
= | | `-3` | `-6` | `-3` | | | `-6` | `-12` | `-6` | | | `-3` | `-6` | `-3` | |
|
This material is intended as a summary. Use your textbook for detail explanation.
Any bug, improvement, feedback then