Use finite approximation to estimate the area under the graph of f(x) = 8x" and above the graph of f(x) = 0 from x, = 0 to X, = 12 using i) a lower sum with two rectangles of equal width. ii) a lower sum with four rectangles of equal width. ili) an upper sum with two rectangles of equal width. iv) an upper sum with four rectangles of equal width.Estimate the area under the graph of f(x) = 4x" between x =0 and x = 8 using each finite approximation below. a. A lower sum with two rectangles of equal width b. A lower sum with four rectangles of equal width c. An upper sum with two rectangles of equal width d. An upper sum with four rectangles of equal widthUsing rectangles each of whose height is given by the value of the function at the midpoint of the rectangle's base (the midpoint rule), estimate the area under the graph of the following function, using first two and then four rectangles. f(x) = - - between x = - and x = 1