For the function [tex]y=\sqrt{x}[/tex] the domain is [tex]x\ge 0.[/tex]
Consider function [tex]y=\sqrt{5-x}.[/tex]
The expression under the root should be greater or equal to zero:
[tex]5-x\ge 0,\\-x\ge -5,\\x\le 5.[/tex]
Answer: the domain of the function [tex]y=\sqrt{5-x}[/tex] is [tex]x\le 5.[/tex]
