jasoncurious Posted December 15, 2012 Share Posted December 15, 2012 (edited) Hi all, there's this function: y=(x^2-6*x+5)/(x-1) which can be reduced to y=(x-5)(x-1)/(x-1) and then to y=x-5 The question asked me to determine the domain and range of this function. Here's the problem, when the function is y=(x^2-6*x+5)/(x-1), the domain is every real number except 1. But when it's been reduced to y=x-5, the domain should be every real number. However, the answer stated that the domain is still every real number except 1. How should I solve this problem? Edited December 15, 2012 by jasoncurious Link to comment Share on other sites More sharing options...
ajb Posted December 15, 2012 Share Posted December 15, 2012 This is a technicality, but the domain of the two functions you give, a rational function and its reduction are different. By reduction you have removed the "division by zero" problem. I think it is now an issue of convention as to what you state as the domain. It looks like your book (or teacher) is considering the domain before reduction. Thus you get all values except x=1. Link to comment Share on other sites More sharing options...
jasoncurious Posted December 17, 2012 Author Share Posted December 17, 2012 Thanks, so I assume this type of to be contextual? Link to comment Share on other sites More sharing options...
ajb Posted December 17, 2012 Share Posted December 17, 2012 Thanks, so I assume this type of to be contextual? Yes, it is contextual and partly an issue of conventions. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now