If f(x,y,z) =xy + yz + zx, then `f_(x) - f_(z)` is equal to

If f(x,y,z) = sin (xy) + cos(xz) , then f_("xx") is

If (x + y + z) = 16 and xy + yz + zx = 75, then x ^(3) + y ^(3) + z ^(3) - 3xyz is

Consider the set of equation x+y+xy=35,y+z+yz=8,z+x+zx=3 . If z_(1),z_(2) are possible values of z, then |z_(1)-z_(2)| is equal to

Let V(x,y,z) =xy + yz + zx, x,y,z in R . Find the differential dV.