Given f(x,y)=7x3cos(y6)\displaystyle {f{{\left({x},{y}\right)}}}={7}{x}^{{3}}{\cos{{\left({y}^{{6}}\right)}}}, find

fxy(x,y)\displaystyle {{f}_{{{x}{y}}}{\left({x},{y}\right)}} =  

fyy(x,y)\displaystyle {{f}_{{{y}{y}}}{\left({x},{y}\right)}} =