I am trying to derivate the equation T(t) = c'(t)/||c'(t)|| ||c'(t)|| being the norm of c'(t). ||T(t)||= 1 and I need to solve for T'(t) I keep getting stuck with some nasty terms. I assume that I need to deal with the norm as the square root of the dot product of c'(t) with itself. Any help would be much appreciated. I have a feeling there is a simpler way to solve this than the way I have been trying.