EXERCISE 3.103. Let \"y : R :- R3 be a helix of the form 7(6) : (cos 6, sin 6, 66'), where c 7E D is a constant, shown green in Fig. 3.39. For each value of 9, consider the innite line (shown red) through 7(9) that is parallel to the Qty-plane and intersects the zaxis. The union of all these lines is called a helicoid, Visualized as the surface swept out by the propeller of a rising helicopter (or lowering if c