1. Power of matrix
`A^2=A*A`
`A^3=A^2*A`
`A^4=A^3*A`
`A^5=A^4*A`
Examples
1. Find `A^2` ...
`A=[[3,1,1],[-1,2,1],[1,1,1]]`
Solution:
`A^2` | = | `A×A` | = | | `3` | `1` | `1` | | | `-1` | `2` | `1` | | | `1` | `1` | `1` | |
| × | | `3` | `1` | `1` | | | `-1` | `2` | `1` | | | `1` | `1` | `1` | |
|
= | | `3×3+1×-1+1×1` | `3×1+1×2+1×1` | `3×1+1×1+1×1` | | | `-1×3+2×-1+1×1` | `-1×1+2×2+1×1` | `-1×1+2×1+1×1` | | | `1×3+1×-1+1×1` | `1×1+1×2+1×1` | `1×1+1×1+1×1` | |
|
= | | `9-1+1` | `3+2+1` | `3+1+1` | | | `-3-2+1` | `-1+4+1` | `-1+2+1` | | | `3-1+1` | `1+2+1` | `1+1+1` | |
|
= | | `9` | `6` | `5` | | | `-4` | `4` | `2` | | | `3` | `4` | `3` | |
|
`A^2` | = | | `3` | `1` | `1` | | | `-1` | `2` | `1` | | | `1` | `1` | `1` | |
| 2 |
| = | | `9` | `6` | `5` | | | `-4` | `4` | `2` | | | `3` | `4` | `3` | |
|
2. Find `B^2` ...
`B=[[2,3,1],[0,5,6],[1,1,2]]`
Solution:
`B^2` | = | `B×B` | = | | `2` | `3` | `1` | | | `0` | `5` | `6` | | | `1` | `1` | `2` | |
| × | | `2` | `3` | `1` | | | `0` | `5` | `6` | | | `1` | `1` | `2` | |
|
= | | `2×2+3×0+1×1` | `2×3+3×5+1×1` | `2×1+3×6+1×2` | | | `0×2+5×0+6×1` | `0×3+5×5+6×1` | `0×1+5×6+6×2` | | | `1×2+1×0+2×1` | `1×3+1×5+2×1` | `1×1+1×6+2×2` | |
|
= | | `4+0+1` | `6+15+1` | `2+18+2` | | | `0+0+6` | `0+25+6` | `0+30+12` | | | `2+0+2` | `3+5+2` | `1+6+4` | |
|
= | | `5` | `22` | `22` | | | `6` | `31` | `42` | | | `4` | `10` | `11` | |
|
`B^2` | = | | `2` | `3` | `1` | | | `0` | `5` | `6` | | | `1` | `1` | `2` | |
| 2 |
| = | | `5` | `22` | `22` | | | `6` | `31` | `42` | | | `4` | `10` | `11` | |
|
This material is intended as a summary. Use your textbook for detail explanation.
Any bug, improvement, feedback then