Question

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

• A. $(0,\infty )$
• B. $(-\infty ,0)$
• C. $(-\infty ,0]$
• D. $R$

Answer 1

The correct option is B $(-\infty ,0)$

$f\left(x\right)$ is defined if $|x|-x>0$
$\Rightarrow |x|>x$
$\Rightarrow x<0$