Results 1 to 2 of 2

Math Help - Elem. Linear Alg.

  1. #1
    Member
    Joined
    Mar 2008
    Posts
    128

    Elem. Linear Alg.

    Hi guys,

    I took "baby" linear algebra over the summer and now I'm in calc III and we do a mini-linear algebra unit at the end of Calc III. Unfortunately, I don't have my old linear algebra book to use as a reference which is truly unfortunate. If someone could get help me get my wheels churning on a few problems I would really appreciate it!

    If matrices A and B are invertible, show that (AB)^{-1}=B^{-1}A^{-1}
    Follow Math Help Forum on Facebook and Google+

  2. #2
    o_O
    o_O is offline
    Primero Espada
    o_O's Avatar
    Joined
    Mar 2008
    From
    Canada
    Posts
    1,407
    Just go by definition. If A is a square matrix and there exists another matrix B such that AB = BA = I, then B is the inverse of A.

    So, all you have to show is that: (AB)\left(B^{-1}A^{-1}\right) = \left(B^{-1}A^{-1}\right)(AB) = I
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Help with elem. proof
    Posted in the Number Theory Forum
    Replies: 6
    Last Post: January 19th 2011, 01:42 PM
  2. Help with Elem. Linear Algebra Proof?
    Posted in the Advanced Algebra Forum
    Replies: 2
    Last Post: July 29th 2009, 06:53 PM
  3. Need Help with Elem. Linear Algebra Problem
    Posted in the Advanced Algebra Forum
    Replies: 3
    Last Post: July 18th 2009, 02:54 PM
  4. Elem. proof help?
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: July 7th 2009, 01:33 PM
  5. elem.num.theo - GCD
    Posted in the Number Theory Forum
    Replies: 7
    Last Post: October 9th 2008, 02:23 PM

Search Tags


/mathhelpforum @mathhelpforum