Find fx, fy, and fz, and evaluate each at the given point.
f(x, y, z) = xy/x + y + z, (3, 1, −1)
fx(x, y, z)=
fy(x, y, z)=
fz(x, y, z)=

fx(3, 1, −1)=
fy(3, 1, −1)=
fz(3, 1, −1)