Answer: Choice D) [tex]x \ge -6[/tex]
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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.
[tex]\frac{1}{3}x+2 \ge 0\\\\\frac{1}{3}x \ge 0-2\\\\\frac{1}{3}x \ge -2\\\\x \ge 3(-2)\\\\x \ge -6[/tex]
If x is -6 or larger, then [tex]\frac{1}{3}x+2[/tex] 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.
