Question

How do you find the domain of a graph? (Please be simple/dumb it down)

Answer 1

The domain is the set of all numbers that are x-coordinates.
Here are some things to look out for:
For a straight line (except a vertical line), the domain is all real numbers.
If there is a fraction with x in the denominator, you must exclude all values of x that would cause a zero in the denominator.
If there is a square root, you must exclude all values of x that would cause a square root of a negative number.

Answer 2

try this
http://www.khanacademy.org/math/algebra/algebra-functions/domain_and_range/v/domain-of-a-function

Answer 3

thanks guys