To determine a reasonable domain for the function, we need to consider the context and restrictions of the problem. In this case, we can establish the following domain:
Since the problem mentions that Jacob rides at a constant speed and takes the same route to and from the library, it implies that he spends a specific amount of time going to the library and an equal amount of time returning home. Therefore, the total time Jacob rides the scooter will be twice the amount of time it takes him to reach the library.
Let's assume it takes Jacob t minutes to reach the library (one way). Therefore, his total riding time will be 2t minutes (to and from the library). To ensure a reasonable domain, we need to consider that he rides for this given time or less.
Hence, a reasonable domain for the function would be [0, 2t]. This means the function is defined for all values of x between 0 and 2t, inclusive.