$[5]$ A particle slides along the hyperbolic paraboloidal surface $z=x\frac{y}{2}$ such that $x=$

$6cos(ku),y=-6sin(ktu),$ where $x,y,$ and in $z$ are in meters and $w$ is a parameter. Determine

the path variable unit vectors, the radius of curvature, and the torsion of the path at the

position where $ku=2\frac{}{3}.$