# Homework Hints 15-5

### 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/

Dr. Math is a registered trademark. This is an excellent site at which you can search to see if your question has been previously asked, or you can send your question directly to Dr. Math to receive an answer.
http://mathforum.org/dr.math/

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/

Problems 1-2
These are asking for you to restate definitions using your own words. Look up these definitions in this section, study them, and then paraphrase them with the answers to these problems.
Problems 3-14
Review the definition of a function and then look at Example 1.
Problems 15-20
These are function machines. Drop in the given value, look at the front of the machine for the rule to see what drops out, as shown in Example 3.
Problems 21-26
For each of these, replace the x by the given value and then simplify the resulting expression as shown in Example 4.
Problems 27-32
Imagine a vertical line sweeping from left to right as shown in Example 6.
Problems 33-38
Set up a table of values; draw the coordinate axes…. be sure to label both the x– and y-axes. Set a scale and plot the point from your table as values. See Example 7. You also might wish to review the types of functions listed just above Example 7.
Problems 39-44
Step 1: First write down the function f.
Step 2: Next, evaluate this function for the value x + h. Simplify this expression.
Step 3: Third, subtract the answer from Step 1 from the answer from Step 2.
Step 4: Finally, divide your answer from Step 3 by h. Factor the numerator, if possible, and simplify.
This process (Steps 1-4) is shown in Example 5.