Which value of [tex]\( x \)[/tex] is in the domain of [tex]\( f(x) = \sqrt{x-2} \)[/tex]?

A. [tex]\( x = -2 \)[/tex]

B. [tex]\( x = 0 \)[/tex]

C. [tex]\( x = 1 \)[/tex]

D. [tex]\( x = 2 \)[/tex]



Answer :

To determine which value of [tex]\( x \)[/tex] is in the domain of the function [tex]\( f(x) = \sqrt{x-2} \)[/tex], we need to ensure that the expression inside the square root is non-negative. Square roots are only defined for non-negative values. Thus, the expression [tex]\( x-2 \)[/tex] must be greater than or equal to zero.

Let's solve the inequality step-by-step:

1. Write the inequality:
[tex]\[ x - 2 \geq 0 \][/tex]

2. Solve for [tex]\( x \)[/tex]:
[tex]\[ x \geq 2 \][/tex]

This means that for [tex]\( f(x) \)[/tex] to be defined, [tex]\( x \)[/tex] must be at least 2 or greater.

Now, let's evaluate each of the provided choices:

- A. [tex]\( x = -2 \)[/tex]:
[tex]\[ -2 - 2 = -4 \quad (\text{which is less than } 0) \][/tex]
So, [tex]\( \sqrt{-4} \)[/tex] is not defined.

- B. [tex]\( x = 0 \)[/tex]:
[tex]\[ 0 - 2 = -2 \quad (\text{which is less than } 0) \][/tex]
So, [tex]\( \sqrt{-2} \)[/tex] is not defined.

- C. [tex]\( x = 1 \)[/tex]:
[tex]\[ 1 - 2 = -1 \quad (\text{which is less than } 0) \][/tex]
So, [tex]\( \sqrt{-1} \)[/tex] is not defined.

- D. [tex]\( x = 2 \)[/tex]:
[tex]\[ 2 - 2 = 0 \quad (\text{which is equal to } 0) \][/tex]
So, [tex]\( \sqrt{0} \)[/tex] is defined and equal to 0.

Given the inequality [tex]\( x \geq 2 \)[/tex], the only choice that satisfies this condition is [tex]\( x = 2 \)[/tex].

Therefore, the value of [tex]\( x \)[/tex] that is in the domain of [tex]\( f(x) = \sqrt{x-2} \)[/tex] is:
[tex]\[ \boxed{2} \][/tex]