By writing one command and using the colon to address ranges of elements (do not type individual elements explicitly), use the matrix a to: create a six-element row vector named p1a that contains the elements of the second row of a. create a 3 x 2 matrix named p1b whose first column is the sixth column of a and the second column is the first 3 elements of row 2 in a. create a five-element row vector named _p1c_that contains the first two elements of the third row of a and the last three element of the first row of a.