Question 750755
Domain is possible x-values and range is possible y-values or function values (f(x)).

So let's look at the function:

{{{f(x)= sqrt(8-2x)}}}

Unless we are dealing with imaginary numbers, which I'm going to assume we're not, then:

You can not take the square root of a negative number, so 8-2x has to be greater than or equal to zero.  Solving that expression will show that x is less than or equal to 4.  Therefore, the domain is negative infinity to 4, and the range is 0 to infinity.