> vector([x,y]) &* evalm(A) &* matrix(2,1,[x,y]) > 0;
                                     [fxx    fxy]    [x]
                       0 < [x, y] &* [          ] &* [ ]
                                     [fyx    fyy]    [y]

# and the inequality is true for all possible values of x and y as long
as they are not both zero. Notice that this simplifies to,
> collect(evalm(vector([x,y]) &* evalm(A) &* matrix(2,1,[x,y]))[1],[x,y]) > 0;
                              2                      2
                     0 < fxx x  + (fyx + fxy) y x + y  fyy

>