Answers/Hints/Solutions for selected Problems in Chapter 12 (answers to most odd-numbered problems are provided in the back of the textbook). Some of the graphs that appear below are links to software pages (holding your mouse pointer over a graph will show if it is such a link).
NOTE: If you are not familiar with DPGraph or have not downloaded it yet, it is necessary to start from the Software page to download the DPGraph software and familiarize yourself with its basics before trying to produce graphs similar to those that appear on this page.

# 13 - The region R in this problem is shaded in color below: