Definite Integrals and Area
Definite integrals can be used to find the area under, over, or between curves. If a function is strictly positive, the area between it and the x axis is simply the definite integral. If it is simply negative, the area is -1 times the definite integral. If finding the area between two positive functions, the area is the definite integral of the higher function minus the lower function, or the definite integral of (f(x)-g(x)).