Re: Linear algebra, matrices, and you
But that's not necessarily true. If you have a 2 x 2 matrix, the possible matrices I see working in addition to the identity matrix are
Err, have to edit these made a mistake
-1 0
0 -1
0 1
1 0
0 -1
-1 0
For example, if your matrix is [0 -1 : -1 0], multiplying by it's transpose is
0(0) + (-1)(-1) (0)(-1) + (-1)(0)
0(-1) + (0)(-1) (-1)(-1) + (0)(0)
Which is [1 0 : 0 1], an identity 2 x 2 matrix. I dunno if I"m doing something wrong, but I don't think we can prove it's definately an identity matrix
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