The diag function has several uses, one of which is to take a vector as its input and create a square matrix with that vector on the diagonal. Create a 21-by-21 matrix with the sequence 10 to 0 to 11...

The diag function has several uses, one of which is to take a vector as its input and

create a square matrix with that vector on the diagonal. Create a 21-by-21 matrix

with the sequence 10 to 0 to 11 (i.e., 11, 10, … , 1, 0, 1, …, 11). [5]