Let y(s) = (x(s), y(s), z(s)) for s ( 0, 1 be a curve in 3D parametriza with respect to arc-length. We define . T(s) = (s) : the unit velocity vector at s;dT (s) . N(s) = : the unit normal vector (recall that k(s) = (8) 11. ) K (S) . B(s) = T(s) x N(s) : the binormal vector.1. What is the arc-length of y? 2. Show that T(s) X N(s) = B(s); N(s) X B(s) = T(s); B(s) X T(s) = N(s). Hint: Recall that given three vectors a, b, c E R3 we have the following relation between cross and dot product: a x (b x c) = (a . c)b - (a - b)c