The following exercises are meant to be answered by few lines of MATLAB code; most of them could be expressed in a single line of code or command. The command may be involved (i.e., it may use a number of parentheses or calls to functions) but can, in essence, be solved by the execution of a single command. If the problem is too complicated, feel free to break it up over two or more lines and later to collapse it into a single line.

2. Given the array A = [ 2 4 1 ; 6 7 2 ; 3 5 9], provide the commands needed to a. assign the first row of A to a vector called x1

b. assign the last 2 rows of A to an array called y

c. compute the sum over the columns of A stored in AC

d. compute the sum over the rows of A stored them in AR

e. compute the standard error of the mean of each column of A (NB. the standard error of the mean is defined as the standard deviation divided by thesquare root of the number of elements used to compute the mean.)