Answer: Choice D)
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Step-by-step explanation:
Taking the square root of a negative number leads to a nonreal result.
So we want the radicand to be 0 or positive
Set the stuff under the square root to be 0 or larger. Solve for x.
If x is -6 or larger, then
is 0 or larger leading to some real number for f(x).
The inequality sign does not flip because we multiplied both sides by a positive number. The inequality sign only flips when we multiply both sides by a negative number.