Hi. I'm not sure if anyone here knows MATLAB, but I'm horrible with it. I have to write a program, which I actually figured out how to do, except that I have to first construct a certain matrix. I found one way to do it, but I'm sure it's not how my teacher wants it. Let A be the nxn matrix with elements aij = -1 for i > j, aii=ain=1, 1<=i<=n, and zero everywhere else. The only thing I've been successful with is to do this: B=eye(n,n);B(1:n,n)=1; (This puts 1's on the diagonal and in the last column) C=tril(-ones(n,n),-1); (This creates a lower triangular matrix with -1's below the diagonal) Then, A = B+C. I am sure there must be a more efficient way to construct this matrix that my teacher is expecting, but I'm not sure what it is. Does anyone who has experience with MATLAB know how I might be able to do this? Thank you!