Let vec$(x)(t)=(3t-t^3,3t^2,3t+t^3)$ be a parametrization of a space curve.

$($i$)(10$ pts$)$ Find the curvature of the curve

$(t)=\frac{||vec(x{)}^{\text{'}}\text{v}\text{e}\text{c}(x{)}^{\text{'}\text{'}}||}{||vec(x{)}^{\text{'}}|{|}^3}$

$($ii$)(15$pts$)(?)$