What is the domain of the function [tex]f(x)=\sqrt{\frac{1}{3} x+2}[/tex]?

A. [tex]x \leq -6[/tex]
B. [tex]x \ \textgreater \ 6[/tex]
C. [tex]x \ \textless \ 6[/tex]
D. [tex]x \geq -6[/tex]



Answer :

To determine the domain of the function [tex]\( f(x) = \sqrt{\frac{1}{3}x + 2} \)[/tex], we need to identify the values of [tex]\( x \)[/tex] for which the expression under the square root is non-negative (since the square root of a negative number is not defined in the set of real numbers).

Here are the steps to find the domain:

1. Set the expression inside the square root to be non-negative:
[tex]\[ \frac{1}{3}x + 2 \geq 0 \][/tex]

2. Solve the inequality for [tex]\( x \)[/tex]:
- First, isolate [tex]\( x \)[/tex] by subtracting 2 from both sides:
[tex]\[ \frac{1}{3}x \geq -2 \][/tex]

- Next, multiply both sides of the inequality by 3 to solve for [tex]\( x \)[/tex]:
[tex]\[ x \geq -6 \][/tex]

3. Interpret the result:
- The inequality [tex]\( x \geq -6 \)[/tex] means that [tex]\( x \)[/tex] must be greater than or equal to [tex]\(-6\)[/tex] for the expression inside the square root to be non-negative.

Therefore, the domain of the function [tex]\( f(x) = \sqrt{\frac{1}{3}x + 2} \)[/tex] is:
[tex]\[ x \geq -6 \][/tex]

So the correct answer is:
[tex]\[ x \geq -6 \][/tex]