# Homework Hints 9-3

Problems 1-4
There are many problems throughout the text labeled IN YOUR OWN WORDS. Just relax; do not be afraid to give your opinion. For the most part, these questions do not have “right” or “wrong” answers. You should spend about five minutes in answering each of these questions.

Problems 5-14
Compare with Figure 9.37. Think of each figure painted on a piece of elastic inner tube. If you can stretch into the other (without tearing), then they are equivalent. For example, in Problem 5, the circle can be transformed into a triangle.

Problems 15-18
Review the definition of a closed figure.

]Problems 19-28
Compare with Figure 9.38.

Problems 29-32
Compare with Figure 9.37. Use the fonts shown in the book to make your decisions, because some fonts can change the topological properties of certain letters.

Problems 33-41
These problems explore the concept of inside/outside.

Problem 42
Read the section of the text discussing the four color problem.

Problems 43-47
These problems can be done by experimentation. Simply try drawing and coloring these maps.

Problem 48
This problem explores a variation of the four-color problem. Read the section of the text discussing the four color problem.

Problem 49
This problem explores a variation of a fractal curve. Read the section of the text discussing the fractal geometry.

### Note: Homework Hints are given only for the Level 1 and Level 2 problems.

However, as you go through the book be sure you look at all the examples in the text. If you need hints for the Level 3 problems, check some sources for help on the internet (see the LINKS for that particular section. As a last resort, you can call the author at (707) 829-0606.

On the other hand, the problems designated “Problem Solving” generally require techniques that do not have textbook examples.

There are many sources for homework help on the internet.

Algebra.help
Here is a site where technology meets mathematics. You can search a particular topic or choose lessons, calculators, worksheets for extra practice or other resources.
http://www.algebrahelp.com/

Quick Math
This site provides online graphing calculators. This is especially useful if you do not have your own calculator.
http://www.quickmath.com/

The Math Forum @ Drexel
This site provides an internet mathematics library that can help if you need extra help. For additional homework help at this site, click one of the links in the right-hand column.
http://mathforum.org/