compute curvature and torsion

Questions
,
1

sorry for my poor english.
this is my first time using mathematica and dont’ know how to compute curvature and torsion
here is the question:
giving a parameterized space curve:
x(u)=(2+cos3u)cosu
y(u)=(2+cos3u)sinu
z(u)=rsin(nu)
please compute the curvature ?(s) and torsion ?(s), where s is the arc length

what mathematica 10 language should i use?

2

Become familiar with Wolfram resources like Curvature and Torsion as well as with the syntax of the Wolfram Language … you know: 6 months in the lab can you save 10 minutes in the library.

3

au_zeus3200,

if you have Mathematica v10 check FrenetSerretSystem[] function in addition to the (very illustrative) suggested demo.
The build-in function can compute all relevant parameters for arbitrary curve:

Clear[a, b, c] ;
res = FrenetSerretSystem[{a[t], b[t], c[t]}, t]

a[t_] = Cos[t];
b[t_] = Sin[t];
c[t_] = t/2 ;

First@Simplify[res]

I.M.