How do you determine the domain and range of a function expressed with an equation?

Question

anonymous · Answer

$$2-\sqrt{x}$$

ganeshie8 · Answer

do you know the domain and range of $\sqrt{x}$ ?

anonymous · Answer

domain is $$(-\infty,\infty)$$ 
range is $$[-3, \infty)$$

ganeshie8 · Answer

Nope. $\sqrt{x}$ function is defined only for `nonnegative` $x$, so the domain of $\sqrt{x}$ is $x \ge  0$

(assuming the given function is real valued)

ganeshie8 · Answer

In your interval notation domain of $\sqrt{x}$ is $[0, \infty)$  and range is $[0, \infty)$

ganeshie8 · Answer

see if you can use that info to find out the domain and range of given function

anonymous · Answer

the domain is $$[0,\infty)$$ and the range is $$[2,\infty)$$???

ganeshie8 · Answer

Excellent !

ganeshie8 · Answer

how did u figre that out ? xD

anonymous · Answer

the question had a 2 in it so i figured that had something to do with either the range or the domain and basically i guessed.