# Why are these arrows not plotting?

I'm very new to mathematica, so pardon me for such a simple question. I have tried to follow the syntax of the "Arrow" documentation(https://reference.wolfram.com/language/ref/Arrow.html), but I cannot seem to add arrows to this Parametric Plot. I have no issue plotting a point to the plot (the red dot), but the arrows will not add. Can you spot the problem? Thank you for your time.

x = {4*Cos[s/5], 4*Sin[s/5], 3*s/5}
pointOfInterest = {0, 4, 3*Pi/2};
tangentv = pointOfInterest + {-4/5, 0, 3/5};
normalv = pointOfInterest + {0, -1, 0};
binormalv = pointOfInterest + {3/5, 0, 4/5};
Show[
(*Sorting the curve itself and orientation.*)
ParametricPlot3D[{{x}},
{s, 0, 10}] /.
(*Adding the point, and corresponding vectors.*)
Graphics3D[{Red, PointSize[0.04], Point[{pointOfInterest}]}],
Graphics3D[{Arrow[Line[{{pointOfInterest}, {tangentv}}]]}],
Graphics3D[{Arrow[Line[{{pointOfInterest}, {normalv}}]]}],
Graphics3D[{Arrow[Line[{{pointOfInterest}, {binormalv}}]]}]]


Thanks very much for your help.

Remove the braces around pointOfInterest, tangentv, normalv and binormalv,that is, use Graphics3D[{Arrow[Line[{pointOfInterest, tangentv}]]}] instead of Graphics3D[{Arrow[Line[{{pointOfInterest}, {tangentv}}]]}], similarly for other arrows to get:

A more compact way to get the same result is:

Show[ParametricPlot3D[{{x}}, {s, 0, 10}, PlotStyle -> Arrowheads[Table[.05, {5}]]] /.
Line -> Arrow,
Graphics3D[{{Red, PointSize[0.04], Point[{pointOfInterest}]},
Black, Arrow[{pointOfInterest, #} & /@ {tangentv, normalv, binormalv}]}]]


same picture

• Thanks very much, your way is much clearer! Feb 17, 2019 at 16:07
• @MichaelMitchell, my pleasure. Thank you for the accept. And welcome to mma.se.
– kglr
Feb 17, 2019 at 16:09