discussion 1

C24 (page 190) Compute the product AB of the two matrices below.

Matrix A:

1 2 3 -2
0 1 -2 -1
1 1 3 1

Matrix B:

 3
 4
 0
 2

Solution (matrix multiplication):

Matrix AB:

  1*3 + 2*4 + 3*0 +(-2)*2          
  0*3 + 1*4 +(-2)*0 + (-1)*2    
  1*3 + 1*4 + 3*0 + 1*2            

Matrix AB:

   7
   2
   9