Determine the gradient of f(x,y)=x32yz2\displaystyle {f{{\left({x},{y}\right)}}}=-{x}^{{3}}-{2}{y}{z}^{{2}} at the point (2,2,4)\displaystyle {\left(-{2},-{2},{4}\right)}.

f(2,2,4)\displaystyle \nabla{f{{\left(-{2},-{2},{4}\right)}}} =