Which inequality represents all values of [tex][tex]$x$[/tex][/tex] for which the product below is defined?

[tex] \sqrt{x-5} \cdot \sqrt{x+2} [/tex]

A. [tex]x \geq 0[/tex]
B. [tex]x \leq 5[/tex]
C. [tex]x \geq -2[/tex]
D. [tex]x \geq 5[/tex]



Answer :

To determine the values of [tex]\( x \)[/tex] for which the product [tex]\( \sqrt{x-5} \cdot \sqrt{x+2} \)[/tex] is defined, we must ensure that both square roots are defined, which means that the expressions inside both square roots must be non-negative.

Step-by-step solution:

1. Expression under the first square root:
[tex]\[ \sqrt{x - 5} \][/tex]
For this square root to be defined, the expression inside the square root must be greater than or equal to zero:
[tex]\[ x - 5 \geq 0 \][/tex]
Solving this inequality:
[tex]\[ x \geq 5 \][/tex]

2. Expression under the second square root:
[tex]\[ \sqrt{x + 2} \][/tex]
For this square root to be defined, the expression inside the square root must be greater than or equal to zero:
[tex]\[ x + 2 \geq 0 \][/tex]
Solving this inequality:
[tex]\[ x \geq -2 \][/tex]

3. Combining both conditions:
For the product [tex]\( \sqrt{x-5} \cdot \sqrt{x+2} \)[/tex] to be defined, both individual conditions must be satisfied simultaneously. Therefore, [tex]\( x \)[/tex] must satisfy both:
[tex]\[ x \geq 5 \quad \text{and} \quad x \geq -2 \][/tex]
Since [tex]\( x \geq 5 \)[/tex] is more restrictive than [tex]\( x \geq -2 \)[/tex], we take the more restrictive condition. Thus:
[tex]\[ x \geq 5 \][/tex]

Therefore, the inequality representing all values of [tex]\( x \)[/tex] for which [tex]\( \sqrt{x-5} \cdot \sqrt{x+2} \)[/tex] is defined is:
[tex]\[ \boxed{x \geq 5} \][/tex]
This corresponds to option D.

Answer: D. [tex]\( x \geq 5 \)[/tex]