1. The problem statement, all variables and given/known data Find the unit speed curve alpha(s) with k(s)=1/(1+s^2) and tau defined as 0. 2. Relevant equations Use the Frenet-Serret equations K(s) is the curvature and tau is the torsion T= tangent vector field (1st derivative of alpha vector) N= Normal vector field (T'/k(s)) B= Binormal vector field (T x N) K(s) is defined as the norm of T' 3. The attempt at a solution Ok I wrote out the matrix for the Frenet-Serret and found the differential equations to solve: T' = T/(1+s^2) *which implies => (alpha(s))'' = (alpha(s))'/(1+s^2) N'= -N/(1+s^2) *which implies =>N' = -(alpha(s)''/(1+s^2) B'=0 Which so far is really quite easy. But here is the kicker, when I try to solve the diff. eq's and go back and check my solutions, my k(s) value is not correct. I feel rather stupid for asking this, but I seem to have forgotten how to treat a systems of diff. eqs. Any thing to kick start my memory for solving this system would be great. Thanks for any help in advanced.