Consider the function [tex]f(x) = \sqrt{5x - 5} + 1[/tex].

Which inequality is used to find the domain?

A. [tex]5x - 4 \geq 0[/tex]
B. [tex]\sqrt{5x - 5} + 1 \geq 0[/tex]
C. [tex]5x \geq 0[/tex]
D. [tex]5x - 5 \geq 0[/tex]



Answer :

To determine the domain of the function [tex]\( f(x) = \sqrt{5x - 5} + 1 \)[/tex], we need to focus on the expression inside the square root, which is [tex]\( 5x - 5 \)[/tex]. For the square root function to yield real numbers, its argument must be non-negative (i.e., greater than or equal to zero). We need to ensure that the expression [tex]\( 5x - 5 \)[/tex] is non-negative.

Let's set up the inequality:

[tex]\[ 5x - 5 \geq 0 \][/tex]

Now, we solve this inequality for [tex]\( x \)[/tex]:

1. Add 5 to both sides of the inequality:
[tex]\[ 5x - 5 + 5 \geq 0 + 5 \][/tex]
[tex]\[ 5x \geq 5 \][/tex]

2. Divide both sides by 5:
[tex]\[ \frac{5x}{5} \geq \frac{5}{5} \][/tex]
[tex]\[ x \geq 1 \][/tex]

Therefore, the domain of the function [tex]\( f(x) = \sqrt{5x - 5} + 1 \)[/tex] is all [tex]\( x \)[/tex] such that [tex]\( x \geq 1 \)[/tex].

Given the options, the inequality that correctly identifies the domain of the function [tex]\( f(x) = \sqrt{5x - 5} + 1 \)[/tex] is:

[tex]\[ 5x - 5 \geq 0 \][/tex]

So, the correct answer is:

[tex]\[ \boxed{5x - 5 \geq 0} \][/tex]