Integrate question

[webmasterpdx]

If the difference is a constant, your CAS answer is correct.
In fact, you could write the answer down and put +10.5 at the end, and it'd be still correct.
ALL constant terms are irrellevant as you have to write the text "+ constant" at the end and this constant is NOT DEFINED. The f(x) portion is only relevant when you define the interval, in which case, all constant terms will be cancelled out.
Note that neither answer is "less accurate" than the other.