Respuesta :
Correct answer is D.
The expression inside the radical must be greater than or equal to zero.
[tex]x \leq 7 \\0 \leq 7-x \\7-x \geq 0[/tex]
Therefore, the x-term inside the radical has a negative coefficient.
The expression inside the radical must be greater than or equal to zero.
[tex]x \leq 7 \\0 \leq 7-x \\7-x \geq 0[/tex]
Therefore, the x-term inside the radical has a negative coefficient.
Consider the funcion [tex] y=\sqrt{x} [/tex]. The dmain of this function is [tex] \ge 0 [/tex] and the range is [tex] y\ge 0 [/tex].
Now if [tex] x\le 7 [/tex] you can calculate that
[tex] x-7\le 0,\\ 7-x\ge 0 [/tex]
and the function [tex] y=\sqrt{7-x} [/tex] will have the domain [tex] x\le 7 [/tex] (state this using that expression under the root is [tex] \ge 0 [/tex]).
As you can see the x-term inside the radical has a negative coefficient.
Answer: correct choice is D.