Results 1 to 4 of 4

Math Help - Inverse of a matrix

  1. #1
    Super Member craig's Avatar
    Joined
    Apr 2008
    Posts
    748
    Thanks
    1
    Awards
    1

    Inverse of a matrix

    Hi just a quick question on matrices, when finding the inverse of the matrix:

    \left(\begin{array}{cc}a&b\\c&d\end{array}\right)<br />

    Would the answer be:

    \frac{1}{ad-bc} \left(\begin{array}{cc}-a&c\\b&-d\end{array}\right)<br />
or \frac{1}{|ad-bc|} \left(\begin{array}{cc}-a&c\\b&-d\end{array}\right)<br />

    Completely forgot if you used the modulus of the determinant or not?

    Thanks in advance

    Craig
    Follow Math Help Forum on Facebook and Google+

  2. #2
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    11
    Awards
    1
    Quote Originally Posted by craig View Post
    Hi just a quick question on matrices, when finding the inverse of the matrix:

    \left(\begin{array}{cc}a&b\\c&d\end{array}\right)<br />

    Would the answer be:

    \frac{1}{ad-bc} \left(\begin{array}{cc}-a&c\\b&-d\end{array}\right)<br />
or \frac{1}{|ad-bc|} \left(\begin{array}{cc}-a&c\\b&-d\end{array}\right)<br />

    Completely forgot if you used the modulus of the determinant or not?

    Thanks in advance

    Craig
    Hi Craig,





    the matrix inverse is

    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Nov 2008
    From
    Paris
    Posts
    354
    blank
    Last edited by clic-clac; January 28th 2009 at 09:02 AM. Reason: error
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Super Member craig's Avatar
    Joined
    Apr 2008
    Posts
    748
    Thanks
    1
    Awards
    1
    Quote Originally Posted by masters View Post
    Hi Craig,





    the matrix inverse is

    Thank you
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Finding the inverse of a matrix using it's elementary matrix?
    Posted in the Advanced Algebra Forum
    Replies: 3
    Last Post: March 7th 2011, 06:08 PM
  2. [SOLVED] Derivative of a matrix inverse and matrix determinant
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: February 24th 2011, 08:18 AM
  3. inverse matrix
    Posted in the Algebra Forum
    Replies: 1
    Last Post: December 2nd 2010, 08:13 PM
  4. Replies: 3
    Last Post: March 1st 2010, 06:22 AM
  5. Inverse matrix
    Posted in the Pre-Calculus Forum
    Replies: 4
    Last Post: July 20th 2006, 08:06 PM

Search Tags


/mathhelpforum @mathhelpforum