Consider the surface S consisting of the part of the cylinder y + z = 16 that lies between the planes x = 1 and x = 4. (a) Find a parametric representation of S. r(s,t) = (s, with SE and t E M with t = [0, 2] 3 1 M (b) Find a parametric representation of the boundary curve of S where x = 1. ri(t) - (1. M with t [0, 2] (c) Find a parametric representation of the boundary curve of S' where x = 4. ry(t) = (4,