Show[{vector3d[{0, 0, 0}, v], vector3d[{0, 0, 0}, w], vector3d[{0, 0, 0}, v[Cross]w, 1]},
Axes -> True, PlotRange -> Automatic, BoxRatios -> Automatic, AxesLabel -> {"x", "y", "z"}, ViewPoint -> {6, 2, 2}]
The above is wrong. There is no v[Cross]w syntax in Mathematica. Try Cross[v,w]
Show[{vector3d[{0, 0, 0}, v], vector3d[{0, 0, 0}, w], vector3d[{0, 0, 0}, Cross[v,w], 1]},
Axes -> True, PlotRange -> Automatic, BoxRatios -> Automatic, AxesLabel -> {"x", "y", "z"}, ViewPoint -> {6, 2, 2}]
