The domain of the function $f(x) = \sqrt{x}$ is

Let $f: R \rightarrow R$ be defined by $f(x) = \frac{1}{x}$ for all $x \in R$. Then $f$ is:

If $[x]^2-5[x]+6=0$,where $[.]$ denotes the greatest integer function,then

If $A$ is the domain and $B$ is the range of the function $f(x) = \begin{cases} 3x-1, & x > 1 \\ x^2+1, & x \leq 1 \end{cases}$ then $A-B=$

Domain of the function $f(x) = \frac{x - 3}{(x - 1)\sqrt{x^2 - 4}}$ is

What is the range of the function $h(x) = \frac{x-2}{x+3}$?