21: 1. Consider the algebraic sigmoid function y : (a) Sketch this sigmoid function as well as the line y : $ \/1+zz2 I for reference. (b) Write a set of inequalities to describe the area between the line and the sigmoid for a? > 0. (c) The same sigmoid shape, now in the yzplane (i.e. z : ~33~), is used as the generating curve for a right cylinder. W Sketch this cylinder by hand