29. Create the following matrix A. 1 2 3 4 5 6 A = 7 8 9 10 11 12 13 14 15 16 17 18 Use the matrix A to: (a) Create a six-element row vector named ha that contains the elements of the first row of A. (b) Create a three-element row vector named hb that contains the elements of the sixth column of A. (c) Create a six-element row vector named hc that contains the first three elements of the second row of A and the last three element of the third row of A.