Answer:
C
Explanation:
the domain is for which values of x is that function defined (is that a valid function).
the range is what values that function can produce based on all the different x-values as input.
so, checking option A
that means all x values are negative.
that means all values inside the square root are negative.
the resulting function values are a discussion class of numbers and not part of the interval of (0, infinity).
so, it cannot be A.
checking option B
the domain range includes the value 6 for x.
but that would make this function for x=6 an invalid expression of 1/0
so, it cannot be B.
checking option C
the value range for x (domain) is x>6 (and excluding x=6).
and the result range is all positive numbers including 0.
there is no violation of any function principle.
the answer is C.
checking option D
similar to C, but the result range is defined as all numbers, negative and positive.
but for the domain the function can never produce negative numbers.
so, it is not D.