2x2? Do it by hand. No dense math involved. One line of code (or so, depending on coding style). If you want to implement or call LINPACK to do a 2x2, you've

2x2? Do it by hand. No dense math involved. One line of code (or so, depending on coding style). If you want to implement or call LINPACK to do a 2x2, you've got other problems.