Find the unit tangent vector.

r (t) = 4t^2i

r'(t) = 8ti

||r'(t)|| = root {(8t)^2} = root {64t^2} = 8t

So, T (t) = 8ti/8t = i.

Yes? No?

I now need the unit normal vector.

I am stuck here again.

I know that T (t) = i (see above).

I need to find T'(t) and ||T'(t)||.