Question 632367
DOMAIN is one of my favorite topics!  It's not nearly as hard as it looks.  You just have to know what is NOT allowed in math, and in this case, what is not allowed is DIVISION BY ZERO.  Anytime you have a denominator, you must NEVER divide by zero, so in this case, the denominator of x-7 must NOT equal zero, so x cannot equal 7.  Domain is ALL VALUES OF X except 7.


For additional explanation on DOMAIN, please see my own website.  Look for the easy-to-remember and easy-to-spell link www.mathinlivingcolor.com.  At the bottom of this page is a link that takes you to my Homepage.  Near the top of the Homepage, look for the link: "Basic, Intermediate, and College Algebra: One Step at a Time."  Choose "Intermediate Algebra" and look in Chapter 1, or Choose "College Algebra" and look in Chapter 2.  


In addition, there are VIDEOS of me teaching these lessons before I retired.  The videos can be found by looking on my Homepage for the link "Rapalje Videos in Living Color."  Choose either Intermediate or College Algebra and look for the video called "Functions, Domain and Range."  


You will probably like my explanations, especially the PRICE of them!!  They are ALL FREE!!  My own students before my retirement thought my books were easier to understand than the traditional books, and many of the solutions are given IN COLOR in the attached "Math in Living Color" pages.  


Most any algebra topic you need is probably there somewhere.  If you need help finding the right page on the website, please send me an Email at rapaljer@seminolestate.edu.  If you like my website, please recommend it to family and friends.


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida