perplexus.info :: Just Math : Matrix Identity

Matrix Identity (Posted on 2007-04-26)

If I is the 2x2 identity matrix, show that there is an infinite number of matrices X with integer members such that X*X = I.

See The Solution Submitted by Brian Smith

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Solution

| Comment 3 of 8 |

Let

        +-           -+
        |             |
        | n     1-n^2 |
    X = |             |
        | 1      -n   |
        |             |
        +-           -+

where n is any integer.

Posted by Bractals on 2007-04-26 13:02:54

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