Answer:
The domain is -418 < a < 8848 where a is an integer.
Step-by-step explanation:
We see from the data given that the domain of T(a) takes both positive and negative integer values ( 8848 meters and -418 meters); T(a) never gets decimal values (and in real life thy won't be of much use because we are not looking for that much accuracy).
So the appropriate number type for the domain of T(a) would be integers. And if you are interested, the domain is -418 < a < 8848.