help me..............

Answer:
(a) The domain of the function is all negative real number
Step-by-step explanation:
Given
[tex]f(x) = -\sqrt{-x[/tex]
Required
Determine the domain
The domain is the possible values of x which f(x) will be defined.
So, for f(x) to be true:, the following condition must be met:
[tex]-x > 0[/tex]
Divide both sides by -1
[tex]x < 0[/tex]
Hence, (a) is true