Let R be the region enclosed by the curves 3:3, 3:4, y=%, and y= %. Let S be the solid of revolution obtained by revolving the region R about the line a.- = 2. The goal of this exercise is to compute the volume of S by using the method of cvlindn'cal shells. a} Let I be a real number in the interval [3: 4]. Consider a typical cylindrical shell ofthiclcness as obtained by revolving about the line I = 2' the thin strip of the region R that lies between I and z + A: For such a shell, nd expressions for its approximate radius 11:) and its approximate height Mr]. r[z) s5