MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Matrices with Mathematica 5.1

  • To: mathgroup at
  • Subject: [mg63331] Re: Matrices with Mathematica 5.1
  • From: Bill Rowe <browe51 at>
  • Date: Sat, 24 Dec 2005 07:18:56 -0500 (EST)
  • Sender: owner-wri-mathgroup at

On 12/23/05 at 5:08 AM, drizkol at (drizkol) wrote:

>I would like to solve the system given by:

>[1  7  -2  0  -8  -3]
>[0  0  1  1    6   5]
>[0  0  0  1    3   9]
>[0  0  0  0    0   0]

>Where the matrix is a typical matrix in the form x1+x2+...+xn = b
>where b is the last item in the row.  For example, row 1 could be
>written as x1 + 7x2 - 2x3 -8x4 = -3.  How could I get mathematica
>to solve this matrix?  I understand how to build a matrix, I just
>need to know the operation to run on it.  I tried to use
>LinearSolve but I did something wrong.  Is there a built-in
>operation to solve these matrices?  If so, please tell.  Thanks.

LinearSolve is the built in function used to solve such a problem. The reason LinearSolve won't work in this case is because your matrix represents an undetermined system. That is taking each column (except the last) to be a variable, you have 5 unknowns and 3 conditions. The last row does nothing for you since it represents the trivial identity 0==0.

  • Prev by Date: Questions regarding MatrixExp, and its usage
  • Next by Date: ExpToTrig with Real Numbers
  • Previous by thread: Re: Matrices with Mathematica 5.1
  • Next by thread: Re: Matrices with Mathematica 5.1