• let f(x)=root log0.5x
• firstly x>0
• and then log0.5>0
• -log2x>0
• log2x<0
• x<1
• x€(0,1)

Hello Abdul Muqsith. Thanks for contacting Careers360 and we hope we will be able to answer your query. 

I am talking about the function f(x)= log x! to the base 0.5.

Note that the function is undefined when x!<0 which never happens in the case of reals. Hence, x should always be greater than 0.