DefinitionAn area between the curve is the region which is bound by two or more curves in a plane. This is determined by taking the definite integral of the upper curve minus lower curve over some range of values. This is a critical idea in calculus for finding the area under curves, the volumes of revolution, optimization problems. It can be found in many places in physics, engineering and economics, but is used in particular to measure regions surrounded by functions. Area between curves example: To calculate the area between two curves y=f(x) and y=g(x) over an interval [a,b], integral ( \int_a^b)