So I probably didn't understand it at first, but from what I learned, integrating two functions that are both below the x-axis would mean that we would do $\int-f(x)-g(x)$ instead of just $\int f(x)-g(x)$. Not sure if thats the case because I just had something where both the functions were under the x-axis on the given interval, and we still had to go by the $\int f(x)-g(x)$ order to solve it correctly. 

Would appreciate some clarification on this matter.

Thanks in advance.