@Carl Love 

hello.

Thank you for the code. I am using the first one you posted

"funcs := [x, 3*x, x^2, 5*x];
for i to nops(funcs) do listM[i] := diff(funcs, [x $ (i-1)]) end do;
M := convert(convert(listM, list), matrix);
linalg:-det(M);"

however, this doesnt work for 2 or 3 elements. it only works with 4 or more

why does this happen?