(a) Use the definition given below with right endpoints to express the area under the curve y = x' from 0 to 1 as a limit. The area A of the region S that is bounded above by the graph of a continuous function y = f(x), below by the x-axis, and on the sides by the lines x = a and x = b is the limit of the sum of the areas of approximationg rectangles. A = lim R = lim [f(x, ) Ax + f(x2 ) Ax + . . . + f(x, )Ax] = lim \\ f(x, ) 4x n - 0o n - a n -00 7=1 lim 7 - 00 (b) Use the following formula for the sum of cubes of the first n integers to evaluate the limit in part (a). 13 + 23 + 33 + ... + 13 = n(n + 1) ]2