This package presents three applications of PSTricks for making LaTeX lecture notes in Calculus. Application 1: Drawing approximations to the area under a graph by rectangles. Application 2: Drawing the vector field of an ordinary differential equation of order one. (The remarks on this application give a way of coloring arrows properly for a vector field.) Application 3: Drawing partitions of a simply connected plane domain. (There is a modified version of this application: AppThreePDF.pdf or AppThreePS.ps.) Author: Le Phuong Quan License: lppl