Q4 Create a new Matlab m-file with the name diagonalSquared.m. You will write a script that builds a n n matrix A that is zero everywhere except along the diagonal, and on the diagonal, the i-th row has entry f. So, if n = 3, then A-1040 The script will have n as a parameter. So, in the first line of diagonalSquared.m, write n-3 (you can change the value of n later on). Your task is to fill out the rest of the script in order to build the matrix A. You must use for loops, and your for loops should involve n. If your code is working properly, and your script is saved in the Current Directory (see instructions previously described), you should be able to examine the matrix A by typing in the command line diagonalSquared (a) Give all the code inside your diagonalSquared.m file. b) The trace of a matrix is the sum of all of the diagonal entries of the matrix. (So, the trace of is 1 +4 = 5). What is the trace of the matrix A described above when n = 20? (The MATLAB function trace might be of use to you.) Also write down the commands you use to calculate this result