Example 3: A closed curve
> x := cos(t)^2;
> y := sin(t)*cos(t);
> z := sin(t);
> PARAM := t = 0..2*Pi;
>
> spacecurve( [x, y, z], PARAM, axes=framed );
>
> animatemotion3d( x, y, z, PARAM, frames=18 ); # default scene is [R,V,A]
>
> animatemotion3d( x, y, z, PARAM, scene=[T,N,B], frames=18 );
>
The fact that the acceleration vector is always in the plane containing the unit tangent and principal unit normal vectors can be seen in
> animatemotion3d( x, y, z, PARAM, scene=[A,T,N], frames=18 );
>