How do you find the domain and range of a function?

Question

anonymous · Answer

There are many functions,
we try an easy one;
                                       y = 2 + x
this is a linear function

anonymous · Answer

Firs you must determine what the values are for variable   X
this is the DOMAIN, in this case X can be any real value
so  Domain f(x) = R

anonymous · Answer

Inmediatly you determine what the values are for Y
this is the RANGE, this case   Y  can be any real number
so      Range f(x) = R

Both cases Domain and Range are the set of Real Numbers = R

anonymous · Answer

well it was a pleasure to help you

anonymous · Answer

Thank you! So here's my other question. I have the function sqrt(9)-x^2.
How do I do it for that problem?

anonymous · Answer

|dw:1353297883854:dw|

anonymous · Answer

you mean this?

anonymous · Answer

Actually it's this:|dw:1353384451994:dw|