# Math Help - domain

1. ## domain

Can anyone help me solve this I cant figure out domain and range no matter how much I study it.
Let f(x)=(x^2+14x+49)/(x+7) or x squared plus 14x plus 49 all over x plus 7
Find the domain.
I want to say that the domain has to be x > or = to -7 (x is greater than or equal to -7).
Thanks
AC

2. for your rational function, the domain is all real numbers except x = -7

domain is the values of x you can use without breaking any rules.

at your level of study, the rules are ...

no division by 0

no square root, fourth root, sixth root, etc. of negative values

no logs of non-positive values.

3. ## I still cant get the correct domain

So if i put the domain in interval notation would it be [-7, Inf) It looks on the graph like that would work but when i enter it in to my online homework it says its wrong. I still dont get what i am doing wrong
Amanda

4. no ... only x = -7 is excluded. your notation $[-7, \infty)$ is the set of all reals greater than -7 and including -7.

here is the domain ...

$(-\infty, -7) \cup (-7, \infty)$

or

${x \in \Re, \, x \neq -7}$