Domain and Range

We can solve this by inspection

Note that when  x = 1   the expression  under the entire radical  is 0

And x cannot be smaller than this   (note if it were, for example, 0,   1 - √2  under the radical would be  negative

And  x  cannot be  larger than 4   because    [2 - √x ]   would result in a negative quantity under a radical

So...the domain  is  [ 1, 4 ]

Here's a graph : https://www.desmos.com/calculator/xxzra4wyai