The domain of the function $f(x) = \frac{1}{\sqrt{|x|-x}}$ is

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

Find the domain and range of the following real function:
$f(x) = -|x|$

The domain of $f(x) = \log \left[(2.5)^{3-x^2} - (0.4)^{x+9}\right]$ is

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 $A-B=$

If $f(x) = [x]^{2} - 5[x] + 6 = 0$,where $[x]$ denotes the greatest integer function,then $x \in$