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Math Help - invertible matrices

  1. #1
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    invertible matrices

    Show that if AB is invertible, so is A.

    (there is a matrix w so that ABW=I.. why?)
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  2. #2
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    Quote Originally Posted by cottekr View Post
    Show that if AB is invertible, so is A.

    (there is a matrix w so that ABW=I.. why?)

    If AB is invertible there exists a matrix W s.t. (AB)W = I. But matrix multiplication is associative, so I = (AB)W = A(BW)...

    Tonio
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  3. #3
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    Quote Originally Posted by cottekr View Post
    Show that if AB is invertible, so is A.

    (there is a matrix w so that ABW=I.. why?)
    That is, pretty much, the definition of "invertible", isn't it?
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