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B Matrix A^(m+1) is different from A^(1+m)?

  1. Oct 9, 2016 #1
    I am confused about a transition matrix as I need to prove that if matrix A is positive, then A^(m+1) is also positive. However, when calculating the (m+1)th transition, I need to put matrix A on the left side of equation (A^m)x=x to write A(A^m)x=x. This to me represents after m times transitions, we are transitioning for the (m+1) times. Intuitively, this yields the result A^(m+1) because we essentially transitioned m+1 times following this matrix. However, mathematically, I can only say that A(A^m) = A^(1+m), which seems to be different from A^(m+1) because of the none-commutative property. Yet they seem to represent the same thing? Are they really equal in this case?
  2. jcsd
  3. Oct 9, 2016 #2
    Yes, they are the same thing: matrix multiplication is associative; i.e. (AB)C = A(BC)
  4. Oct 9, 2016 #3


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    Every matrix commutes with itself.
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