1. Let a curve in 3-space be defined by the two equations Show that the two equations define a tangent vector to the curve. (We write “a tangent vector” rather than “the tangent vector” because is not necessarily of unit magnitude like the tangent vector defined in Eq. (1.9).
2. Prove that if L' is defined by (2.36), then Eq. (2.28) implies Eq. (2.37).