Compute the following matrix?

Compute the following matrix

 

[3 -3] [-1 -2]  [12] 

[1 2] [3 -1] +  [34] 

[1 -3]             [56] 

2 Answers

Relevance
  • 5 months ago

    Did you leave out spaces on the second matrix?  The left side looks like you're multiplying a 3x2 matrix by a 2x2 matrix, which will give you another 3x2 matrix; but the matrix after the + appears to be a 3x1 matrix.  You can't add a 3x2 matrix to a 3x1 matrix.  If you meant:

        [ 3 -3 ]  [-1 -2 ]       [ 1  2 ]

        [ 1  2 ]  [  3 -1 ]  +  [ 3  4 ]

        [ 1 -3 ]                   [ 5  6 ]

    ...then the addition is legal.  The product on the left is:

        [ ((3)(-1) + (-3)(3))   ((3)(-2) + (-3)(-1)) ]

        [ ((1)(-1) + (2)(3))    ((1)(-2) + (2)(-1))  ]

        [ ((1)(-1) + (-3)(3))   ((1)(-2) + (-3)(-1)) ]

           [ (-3 - 9)  (-6 + 3) ]      [ -12  -3 ]

        = [ (-1 + 6)  (-2 - 2) ]  =  [    5  -4 ]

           [ (-1 - 9)  (-2 + 3) ]      [ -10   1 ]

    Add the second 3x2 matrix to get:

            [-11  -1 ]

        =  [  8    0 ]

            [ -5    7 ]

  • alex
    Lv 7
    5 months ago

    I can't guess this kind of matrix !

Still have questions? Get answers by asking now.