(1 point) The area A of the region S that lies under the graph of the continuous function f on the interval [a, b] is the limit of the sum of the areas of approximating rectangles: 1n ã«! h-a where ÎÏ Use this definition to find an expression for the area A under the graph of the functionf(x) = on the interval [2.4]. +1 A= lim