Let \(f\) and \(g\) be continuous on \([a,b],\) and suppose that \(f(x) \geq g(x)\) for all \(x\) in \([a,b].\) Then the area of the region between the graphs of \(f\) and \(g\) and the vertical lines \(x=a\) and \(x=b\) is
$$
A = \int_a^b [f(x) – g(x)] \; dx
$$