Results 1 to 3 of 3

Math Help - Write the inverse of A in terms of the matrix A

  1. #1
    Junior Member
    Joined
    Feb 2010
    Posts
    48

    Write the inverse of A in terms of the matrix A

    I have no idea where to begin, if someone could help me get started.

    Also, I'm a little unsure about what to do for the first question as well (part a).
    Attached Thumbnails Attached Thumbnails Write the inverse of A in terms of the matrix A-q9.jpg  
    Last edited by DarK; October 24th 2010 at 08:37 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Mar 2010
    From
    Florida
    Posts
    3,093
    Thanks
    5
    Matrix multiplication general isn't commutative.

    (A-B)(A+B)=A^2+AB-BA-B^2

    If AB \neq BA, then AB-BA isn't guaranteed to equal to 0.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,707
    Thanks
    1470
    You titled this "write the inverse of A in terms of the matrix A" but then didn't ask about (b)!

    If A^2+ A- I_n= 0 then A(A+ I_n)= (A+ I_n)A= I_n.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Write in lowest terms
    Posted in the Algebra Forum
    Replies: 3
    Last Post: March 4th 2011, 11:56 AM
  2. Write the expressions in terms of cosine?
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: March 11th 2009, 11:27 AM
  3. write in terms of sin and cos
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: November 2nd 2008, 12:32 PM
  4. Write Log In Terms of a and b
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: August 4th 2008, 05:20 AM
  5. write tan10x in terms of tan5x (?!)
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: April 13th 2008, 07:30 PM

Search Tags


/mathhelpforum @mathhelpforum