Results 1 to 5 of 5

Math Help - matrix equation.

  1. #1
    Member
    Joined
    Apr 2010
    Posts
    135

    matrix equation.

    hello can someone please demonstrate how matrix is evaluated by expressing it in echelon form and use row reduction to solve it. it would be a great help.

    k1+ L2+ Z = 20
    3K -L+2Z = 22
    2K+L-4Z=7
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    16,444
    Thanks
    1863
    Quote Originally Posted by sigma1 View Post
    hello can someone please demonstrate how matrix is evaluated by expressing it in echelon form and use row reduction to solve it. it would be a great help.

    k1+ L2+ Z = 20
    3K -L+2Z = 22
    2K+L-4Z=7
    Actually, it is the other way around- row reduce in order to get the echelon form.

    The "augmented matrix" for this system is \begin{bmatrix} 1 & 2 & 1 & 20 \\ 3 & -1 & 2 & 22 \\ 2 & 1 & -4 & 7\end{bmatrix}.

    Now use row operations to put this into echelon form. For example, a first step would be to subtract three times the first row from the second row and subtract two times the first row from the third row:
    \begin{matrix}1 & 2 & 1 & 20 \\ 0 & -7 & -1 & -38 \\ 0 &  -3 & -6 & -33\end{bmatrix}
    That take care of the first row. Now subtract 3/7 times the second row from the third row.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Apr 2010
    Posts
    135
    Quote Originally Posted by HallsofIvy View Post
    Actually, it is the other way around- row reduce in order to get the echelon form.

    The "augmented matrix" for this system is \begin{bmatrix} 1 & 2 & 1 & 20 \\ 3 & -1 & 2 & 22 \\ 2 & 1 & -4 & 7\end{bmatrix}.

    Now use row operations to put this into echelon form. For example, a first step would be to subtract three times the first row from the second row and subtract two times the first row from the third row:
    \begin{matrix}1 & 2 & 1 & 20 \\ 0 & -7 & -1 & -38 \\ 0 &  -3 & -6 & -33\end{bmatrix}
    That take care of the first row. Now subtract 3/7 times the second row from the third row.

    I have tried that but am not arriving at a correct answer. could you please show me what you would get for the matrix in triangular form.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor harish21's Avatar
    Joined
    Feb 2010
    From
    Dirty South
    Posts
    1,036
    Thanks
    10
    Quote Originally Posted by sigma1 View Post
    I have tried that but am not arriving at a correct answer. could you please show me what you would get for the matrix in triangular form.
    You might want to use this to find out where you are going wrong:

    Linear Algebra Toolkit
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Member
    Joined
    Apr 2010
    Posts
    135
    Quote Originally Posted by harish21 View Post
    You might want to use this to find out where you are going wrong:

    Linear Algebra Toolkit
    thanks a million...
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: April 11th 2011, 02:17 AM
  2. Matrix equation
    Posted in the Algebra Forum
    Replies: 1
    Last Post: July 12th 2010, 06:59 AM
  3. an example of a matrix equation
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: September 29th 2009, 07:46 AM
  4. matrix equation
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: June 1st 2008, 01:50 AM
  5. The Matrix Equation Ax=b
    Posted in the Advanced Algebra Forum
    Replies: 7
    Last Post: May 31st 2007, 04:21 PM

Search Tags


/mathhelpforum @mathhelpforum