Chapter 6.2, Problem 2QC

Interpret the area formula when it is written in the form $A={\displaystyle {\int }_a^{b}f\left(x\right)dx-}{\displaystyle {\int }_a^{b}g\left(x\right)dx}$, where $f\left(x\right)\ge g\left(x\right)\ge 0$ on [a, b].