Given that,
[tex]f(x) = \sqrt{x-3}[/tex]
To find,
The domain of f(x).
Solution,
We have, [tex]f(x) = \sqrt{x-3}[/tex]
To find domain,
The term under the square root must be positive or null as follows :
[tex]x-3\ge 0[/tex]
Adding 3 both sides
[tex]x-3+3\ge 0+3\\\\x\ge 3[/tex]
So, the domain is x-3>0 .
