A diagonal matrix is a square matrix with all the entries outside the main diagonal equal to zero (regardless of what the diagonal entries are). A signature matrix is a diagonal matrix where the diagonal entries are either +1 or -1. Write a function isdiagsignature(m) that returns 2 logical values indicating whether the matrix m is a diagonal matrix and a signature matrix, respectively. Do not use Matlab's isdiag) function. Matlab Sample Output >> [a,b] isdiagsignature ([1,0,0; 0,-1,0; 0,0,0] ) _ b- >> [a,b] isdiagsignature ( [ 1,0,0; 0,-1,0; 0,0,1 = >> [a,b] isdiagsignature ([1,0,0; 0,-1,0; 0,0,5] ) = >> [a,b] -sdiagsignature ( [ 1,0,0; 0,-1,0; 0,5,0] )