1. The vector v is a function of the time t and k is a constant vector. Find the time derivatives of (i) |v|2, (ii) (v · k) v, (iii) [v, v, k].
2. Find the unit tangent vector, the unit normal vector and the curvature of the circle x = a cos θ, y = a sin θ, z = 0 at the point with parameter θ.