Can you outline specifically how your textbook does it?
I am trying to find the normal of a curve alpha.
I have got tangent = d(alpha) / d(s)
and k*normal = d(tangent) / d(s)
So I could work out k and then do (d(tangent) / d(s)) / k but my problem sheet does it a different way and then implies k from the above equation (it doesn't specify how though!)
Thanks for any help