I don’t want to waste time to do formula editting so post image instead ;p

Description

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Solution

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Comments

The proof consists of 3 important parts:

  • A normal matrix, with property , is diagonalizable by unitary matrix , with , as ;
  • The column vectors of unitary matrix form a set of orthonormal basis of . As a result arbitrary vector can be reformulated as ;
  • The property to be proven is easily shown when the normal matrix is also a diagonal matrix (As is shown in the Lemma).