# Thread: Torsion - Vector Algebra - urgent kinda

1. ## Torsion - Vector Calculus - urgent kinda

Question :- Find the torsion of $\displaystyle C : r(t) = [t, t^2, t^3]$

Strategy :- First convert into $\displaystyle r(s)$. Then find $\displaystyle u(s)$ (unit tangent vector). Then find the $\displaystyle b(s)$ (unit binormal vector). Then take its derivative and game is up.

Problems :- But....a biiiig BUT....I am stuck ....Till now I have done problems in which there were equations of circles and elipses etc and it was easier to convert them into parametric form and then conert into $\displaystyle r(s)$...here I am atuck with these $\displaystyle t$s....

Questions :- 1. How do I write the parametric forms and convert them from $\displaystyle t$ to $\displaystyle s$ ?
2. How do I find the unit normal vector vector with which I have to cross the unit tangent vector ?

Please take your time answering cuz I am stuck really bad....Thanks a lot...

2. Still no luck with the conversions...Though I found out a pre-defined formula for it but its not the point.