Question: How can I plot a Möbius strip? I tried [this one](http://mathworld.wolfram.com/MoebiusStrip.html), but I can't get it to work:

```
ParametricPlot3D[{
    (5 + s*Cos[u/2]) Cos[u],
    (5 + s*Cos[u/2]) Sin[u],
    (s*Sin[u/2])}, {u, -20, 20}, {s, 0, 2 π}]

```

[![my strip](https://i.stack.imgur.com/z3aQV.png)](https://i.stack.imgur.com/z3aQV.png)

Answer: 
Equation taken form the [wiki](https://en.wikipedia.org/wiki/M%C3%B6bius_strip) page 

```
 x[u_, v_] := (1 + (v/2) Cos[u/2]) Cos[u]
 y[u_, v_] := (1 + (v/2) Cos[u/2]) Sin[u]
 z[u_, v_] := (v/2) Sin[u/2]

 plot = ParametricPlot3D[{x[u, v], y[u, v], z[u, v]}, {u, 0, 
    2 Pi}, {v, -1, 1}, Boxed -> False, Axes -> False]

```

[![enter image description here](https://i.stack.imgur.com/KIBPj.jpg)](https://i.stack.imgur.com/KIBPj.jpg)
Just for fun (using the parametrization from OP hyperlink):

```
mobius[r_, s_,t_] := {r + s Cos[t/2], r + s Cos[t/2], s Sin[t/2]} {Cos[t], Sin[t],
    1}
Manipulate[
 With[{wd = w},
  Row[{
    ParametricPlot[{u, v}, {u, -wd, wd}, {v, 0, 2 Pi}, 
     AspectRatio -> 1/2, Epilog -> {Red, PointSize[0.04], Point@p}, 
     ImageSize -> 200],
    Show[ParametricPlot3D[mobius[r, u, v], {u, -wd, wd}, {v, 0, 2 Pi},
       Mesh -> False, PlotStyle -> Yellow, 
      PerformanceGoal -> "Quality"], 
     Graphics3D[{Red, PointSize[0.04], Point[mobius[r, ##] & @@ p]}], 
     ImageSize -> 200]
    }]], {r, 1, 2}, {w, 0.5, 2}, {{p, {0, 0}}, {{-w, 0}, {w, 2 Pi}}, 
  Slider2D}]

```

[![enter image description here](https://i.stack.imgur.com/keFMO.gif)](https://i.stack.imgur.com/keFMO.gif)