Final answer:
The domain of the function f(x,y) = √(x-25) is all real numbers greater than or equal to 25.
Step-by-step explanation:
The domain of a function is the set of all possible input values, or x-values, for which the function is defined. In this case, the function is f(x,y) = √(x-25). For the function to be defined, the value inside the square root must be non-negative (greater than or equal to zero). So, we set x-25 ≥ 0 and solve for x:
x - 25 ≥ 0
x ≥ 25
Therefore, the domain of the function f(x,y) = √(x-25) is all real numbers greater than or equal to 25.