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Equivalent statements to matrix A is orthogonal

  1. Sep 17, 2013 #1
    A is orthogonal if the A[itex]^{-1}[/itex] = A[itex]^{T}[/itex].

    Thus, AA[itex]^{T}[/itex] = I.

    However, is the statement A is orthogonal equivalent to A[itex]^{2}[/itex]=I.

    I don't think the statements are equivalent, but it comes from a test. Thus, I'd hope the test is correct.
  2. jcsd
  3. Sep 17, 2013 #2


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    Multiply both sides of the A^2=I expression by A^-1 and see what you get.

    From that expression you will be able to see the relationship required for both to be true.
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