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Homework Help: Proving a Linear System

  1. Apr 11, 2010 #1
    1. The problem statement, all variables and given/known data

    let A (2x2 real matrices),

    If AB=BA for all B (2x2 real matrices) , show that A=bI2 for all b ( b are real numbers)

    2. Relevant equations

    N/A

    3. The attempt at a solution

    can anyone give me clue for this one too
     
  2. jcsd
  3. Apr 11, 2010 #2
    Having done the other one, you can definitely do this one. Just formulate it in a similar way.

    AB-BA=0
     
    Last edited: Apr 11, 2010
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