# Domain and range

1. Mar 3, 2008

### dranseth

1. The problem statement, all variables and given/known data
I don't really know how to ask this, so I'll get straight into an example.

x:x$$\in$$(-$$\infty$$,$$\infty$$) but x$$\neq$$1
x:x$$\in$$(-$$\infty$$,1)$$\cup$$(1,$$\infty$$)

what is the difference between these two intervals?

2. Relevant equations

3. The attempt at a solution
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Mar 3, 2008

### Dick

There is no difference. They are both the whole real line except for x=1. Why do you ask?

3. Mar 3, 2008

### dranseth

At times when I look at answers in the back of the book, it is one or the other. There didn't appear to be any consistency, so I was wondering if I was possibly missing something..

4. Mar 4, 2008

### HallsofIvy

Staff Emeritus
Yes, you are missing seeing that they are the same thing!