# Domain Rule

• Jan 16th 2007, 01:27 PM
qbkr21
Domain Rule
If I am trying to calcuate the domain. There is an absolute value, so would I set the part inside the absolute value brackets to: greater than or equal to zero, greater than zero, or not equal to zero. Thanks for the help.
• Jan 16th 2007, 02:23 PM
topsquark
Quote:

Originally Posted by qbkr21
If I am trying to calcuate the domain. There is an absolute value, so would I set the part inside the absolute value brackets to: greater than or equal to zero, greater than zero, or not equal to zero. Thanks for the help.

Perhaps it would help if you posted the function...

-Dan
• Jan 16th 2007, 02:27 PM
qbkr21
I just looking for a general rule...

denominator: =/ (not equal to zero)
square root: >= (greater than = to)
log:> (greater than)
absolute value: ?
• Jan 16th 2007, 02:29 PM
topsquark
Quote:

Originally Posted by qbkr21
I just looking for a general rule...

denominator: =/ (not equal to zero)
square root: >= (greater than = to)
log:> (greater than)
absolute value: ?

Then consider the archetype:
$y = |x|$

This function is defined on all real numbers, so the domain is $( -\infty, \infty)$. The basic idea is that there is a y value for every real x value.

-Dan
• Jan 16th 2007, 03:02 PM
qbkr21
Thanks