The function in question is:

$y = \sqrt{x - 10}$

To determine the domain of this function, we need to ensure that the expression under the square root, $x - 10$, is non-negative, since the square root of a negative number is not defined in the set of real numbers. Thus, we require:

$x - 10 \geq 0$

Solving for $x$:

$x \geq 10$

So, the domain of the function is $x \geq 10$, which corresponds to option A.

Let me know if you need more details or have any questions!

Here are 5 related questions you might explore:

1. What is the range of the function $y = \sqrt{x - 10}$?
2. How do we find the domain of more complex square root functions?
3. What happens if the square root function is under a negative sign, such as $y = -\sqrt{x - 10}$?
4. Can you generalize a rule for finding the domain of any square root function?
5. How would the domain change if the function was $y = \sqrt{x - 5}$?

Tip: When dealing with square root functions, always ensure the expression inside the square root is non-negative to find the correct domain.