5. The graph below shows a vector-valued function. 3.5- a) Sketch the unit tangent vector when x = 2. 2.5- b) Sketch the principal unit normal vector when x = 2. 2- 1.5 c) Which of the following two quantities could not Possibly be equal to zero when x = 2: 1 - a or a ? 0.5- -2 2 x 3 5