Linear algebra: Finding the number of parameters of a system given dimensions and rank












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Suppose the system Ax = b is consistent and A is a 6 x 7 matrix and rank(A) = 2. How many parameters does the system have?










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  • $begingroup$
    The only thing you have to do is to calculate the number of free variables. If $n$ is the number of variables, then $n - r$ is the number of free variables, where $r$ is the rank of the matrix.
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    – thanasissdr
    Apr 2 '16 at 7:03


















1












$begingroup$


Suppose the system Ax = b is consistent and A is a 6 x 7 matrix and rank(A) = 2. How many parameters does the system have?










share|cite|improve this question









$endgroup$












  • $begingroup$
    The only thing you have to do is to calculate the number of free variables. If $n$ is the number of variables, then $n - r$ is the number of free variables, where $r$ is the rank of the matrix.
    $endgroup$
    – thanasissdr
    Apr 2 '16 at 7:03
















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$begingroup$


Suppose the system Ax = b is consistent and A is a 6 x 7 matrix and rank(A) = 2. How many parameters does the system have?










share|cite|improve this question









$endgroup$




Suppose the system Ax = b is consistent and A is a 6 x 7 matrix and rank(A) = 2. How many parameters does the system have?







linear-algebra






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asked Apr 2 '16 at 6:13









user298519user298519

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  • $begingroup$
    The only thing you have to do is to calculate the number of free variables. If $n$ is the number of variables, then $n - r$ is the number of free variables, where $r$ is the rank of the matrix.
    $endgroup$
    – thanasissdr
    Apr 2 '16 at 7:03




















  • $begingroup$
    The only thing you have to do is to calculate the number of free variables. If $n$ is the number of variables, then $n - r$ is the number of free variables, where $r$ is the rank of the matrix.
    $endgroup$
    – thanasissdr
    Apr 2 '16 at 7:03


















$begingroup$
The only thing you have to do is to calculate the number of free variables. If $n$ is the number of variables, then $n - r$ is the number of free variables, where $r$ is the rank of the matrix.
$endgroup$
– thanasissdr
Apr 2 '16 at 7:03






$begingroup$
The only thing you have to do is to calculate the number of free variables. If $n$ is the number of variables, then $n - r$ is the number of free variables, where $r$ is the rank of the matrix.
$endgroup$
– thanasissdr
Apr 2 '16 at 7:03












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Since rank is the no of non zero rows, so there will be 4 zero rows (no of rows are 6, rank is 2, another 4 are zero rows). Each zero row represent 1 parameter. Therefore there will be 4 parameters. Consistent means either many sol or unique sol






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    $begingroup$

    Since rank is the no of non zero rows, so there will be 4 zero rows (no of rows are 6, rank is 2, another 4 are zero rows). Each zero row represent 1 parameter. Therefore there will be 4 parameters. Consistent means either many sol or unique sol






    share|cite|improve this answer









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      0












      $begingroup$

      Since rank is the no of non zero rows, so there will be 4 zero rows (no of rows are 6, rank is 2, another 4 are zero rows). Each zero row represent 1 parameter. Therefore there will be 4 parameters. Consistent means either many sol or unique sol






      share|cite|improve this answer









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        $begingroup$

        Since rank is the no of non zero rows, so there will be 4 zero rows (no of rows are 6, rank is 2, another 4 are zero rows). Each zero row represent 1 parameter. Therefore there will be 4 parameters. Consistent means either many sol or unique sol






        share|cite|improve this answer









        $endgroup$



        Since rank is the no of non zero rows, so there will be 4 zero rows (no of rows are 6, rank is 2, another 4 are zero rows). Each zero row represent 1 parameter. Therefore there will be 4 parameters. Consistent means either many sol or unique sol







        share|cite|improve this answer












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        share|cite|improve this answer










        answered Oct 23 '17 at 15:21









        MeenMeen

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