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Solution
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Solution provided by AtoZmath.com
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is Involutary Matrix calculator
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1. `[[-5,-8,0],[3,5,0],[1,2,-1]]` 2. `[[2,-8,0],[3,5,0],[1,2,-1]]`
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Example1. is Involutary Matrix ? `[[-5,-8,0],[3,5,0],[1,2,-1]]`Solution:A square matrix `A` is called an involutary matrix, if `A^2 = I` where `I` is the identity matrix. `A` | = | | `-5` | `-8` | `0` | | | `3` | `5` | `0` | | | `1` | `2` | `-1` | |
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`A×A` | = | | `-5` | `-8` | `0` | | | `3` | `5` | `0` | | | `1` | `2` | `-1` | |
| × | | `-5` | `-8` | `0` | | | `3` | `5` | `0` | | | `1` | `2` | `-1` | |
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= | | `-5×-5-8×3+0×1` | `-5×-8-8×5+0×2` | `-5×0-8×0+0×-1` | | | `3×-5+5×3+0×1` | `3×-8+5×5+0×2` | `3×0+5×0+0×-1` | | | `1×-5+2×3-1×1` | `1×-8+2×5-1×2` | `1×0+2×0-1×-1` | |
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= | | `25-24+0` | `40-40+0` | `0+0+0` | | | `-15+15+0` | `-24+25+0` | `0+0+0` | | | `-5+6-1` | `-8+10-2` | `0+0+1` | |
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= | | `1` | `0` | `0` | | | `0` | `1` | `0` | | | `0` | `0` | `1` | |
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Here `A^2 = I`, so `A` is an involutary matrix
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