Let $z = f(u,v) = \sin u \cos v$, $u = -3x^2 + y$, $v = -3x + 3y$,
and put $g(x,y) = \left(u(x,y), v(x,y)\right)$. The derivative matrix $\mathbf{D}(f\circ g)(x,y) =$
$($ , $)$
( Leaving your answer in terms of $u, v, x, y$ )