Question

If del f =2xyz³ i + x²z³ j+ 3x²y²z² k find the f(x,y,z) at f(1,-2,2)

Answer 1

$f_x=2xyz^3,~f_y=x^2z^3,~f_z=3x^2yz^2,$

$f=x^2yz^3,$

$f(1,-2,2)=1^2\cdot(-2)\cdot2^3=-16.$